The Cogan House Covered Bridge is a
Burr arch truss
The Burr Arch Truss—or, simply, Burr Truss or Burr Arch—is a combination of an arch and a ''multiple kingpost'' truss design. It was invented in 1804 by Theodore Burr, patented on April 3, 1817, and used in bridges, usually covered bridge ...
covered bridge
A covered bridge is a timber-truss bridge with a roof, decking, and siding, which in most covered bridges create an almost complete enclosure. The purpose of the covering is to protect the wooden structural members from the weather. Uncovered woo ...
over
Larrys Creek
Larrys Creek is a U.S. Geological Survey. National Hydrography Dataset high-resolution flowline dataThe National Map , accessed August 8, 2011 tributary of the West Branch Susquehanna River in Lycoming County in the U.S. state of Pennsylvania. ...
in
Cogan House Township,
Lycoming County
Lycoming County is a county in the Commonwealth of Pennsylvania. As of the 2020 census, the population was 114,188. Its county seat
A county seat is an administrative center, seat of government, or capital city of a county or civil parish. ...
, in the
U.S. state
In the United States, a state is a constituent political entity, of which there are 50. Bound together in a political union, each state holds governmental jurisdiction over a separate and defined geographic territory where it shares its sove ...
of
Pennsylvania
Pennsylvania (; ( Pennsylvania Dutch: )), officially the Commonwealth of Pennsylvania, is a state spanning the Mid-Atlantic, Northeastern, Appalachian, and Great Lakes regions of the United States. It borders Delaware to its southeast, ...
. It was built in 1877 and is long. The bridge was placed on the
National Register of Historic Places
The National Register of Historic Places (NRHP) is the United States federal government's official list of districts, sites, buildings, structures and objects deemed worthy of preservation for their historical significance or "great artistic v ...
in 1980, and had a major restoration in 1998. The Cogan House bridge is named for the
township
A township is a kind of human settlement or administrative subdivision, with its meaning varying in different countries.
Although the term is occasionally associated with an urban area, that tends to be an exception to the rule. In Australia, Ca ...
and village of Cogan House, and is also known by at least four other names: Buckhorn, Larrys Creek, Day's, and Plankenhorn.
The Cogan House Covered Bridge was constructed by a
millwright who assembled the timber framework in a field next to the
sawmill
A sawmill (saw mill, saw-mill) or lumber mill is a facility where logs are cut into lumber. Modern sawmills use a motorized saw to cut logs lengthwise to make long pieces, and crosswise to length depending on standard or custom sizes (dimensi ...
, before it was reassembled at the bridge site. It was the only bridge on Larrys Creek that survived the flood of June 1889, and one of only a handful that were left intact in the county. Although the bridge used to carry a steady flow of
tannery
Tanning may refer to:
*Tanning (leather), treating animal skins to produce leather
*Sun tanning, using the sun to darken pale skin
**Indoor tanning, the use of artificial light in place of the sun
**Sunless tanning, application of a stain or dye t ...
and sawmill traffic, the
clearcutting
Clearcutting, clearfelling or clearcut logging is a forestry/ logging practice in which most or all trees in an area are uniformly cut down. Along with shelterwood and seed tree harvests, it is used by foresters to create certain types of fore ...
of the surrounding forests meant the end of those industries by the early 20th century.
Since then much of the surrounding area has reverted to
second growth forest
A secondary forest (or second-growth forest) is a forest or woodland area which has re-grown after a timber harvest or clearing for agriculture, until a long enough period has passed so that the effects of the disturbance are no longer evident. I ...
, and the one-lane bridge is now on a dead end road in a remote valley with little traffic. It is the oldest and longest of the three covered bridges remaining in the county. Despite the 1998 restoration and other repairs, as of 2009 the bridge structure's sufficiency rating on the
National Bridge Inventory
The National Bridge Inventory (NBI) is a database, compiled by the Federal Highway Administration, with information on all bridges and tunnels in the United States that have roads passing above or below them. That is similar to the grade-crossing ...
was 17.2 percent and its condition was deemed "basically intolerable requiring high priority of corrective action".
Names
The covered bridge is south of
Pennsylvania Route 184
Pennsylvania Route 184 (PA 184, designated by the Pennsylvania Department of Transportation as SR 184) is an state highway located in Lycoming County in Pennsylvania. The western terminus is at PA 287 in Brookside. The east ...
on Campbell Road (Township Road 784), past the intersection with Covered Bridge Road.
Its official name on the National Register of Historic Places (NRHP) is "Cogan House Covered Bridge".
It is the only covered bridge ever built in Cogan House Township and the name comes from the township, as well as the village of Cogan House, which is northeast of the bridge.
Cogan House Township and the village are named for David Cogan, who settled on Larrys Creek in 1825. Cogan was one of the few settlers in the area for many years and grew tired of living nearly alone in the wilderness. In 1842 he abandoned his homestead, as did a neighbor named Carter. Their houses were used by hunters and travelers and the name Cogan's House was given to the area. Cogan House Township was formed from parts of
Jackson
Jackson may refer to:
People and fictional characters
* Jackson (name), including a list of people and fictional characters with the surname or given name
Places
Australia
* Jackson, Queensland, a town in the Maranoa Region
* Jackson North, Qu ...
and
Mifflin Townships on December 6, 1843.
Since the bridge's 1998 restoration, the Lycoming
County Commissioners
A county commission (or a board of county commissioners) is a group of elected officials (county commissioners) collectively charged with administering the county government in some states of the United States; such commissions usually comprise ...
have officially called it the "Buckhorn Covered Bridge".
The name comes from the bridge's location at the base of Buckhorn Mountain,
and from the road to the former village of Buckhorn, which crossed the creek on it.
This is the name used on the
official plaque erected by the commissioners to mark its restoration and placement on the NRHP, despite the different name used on the Register itself.
The commissioners chose "Buckhorn Covered Bridge" based on one of the names used in Benjamin and June Evans' 1993 book ''Pennsylvania's Covered Bridges: A Complete Guide''.
Historically, the commissioners used "Cogan House Covered Bridge" as the official name.
Historian Milton W. Landis uses "Larrys Creek Covered Bridge" since it crosses Larrys Creek, and notes this was the name used by other local historians.
Larrys Creek is named for Larry Burt, who was the first settler at the mouth of the creek when the surveyors came through in 1769.
Landis acknowledges the "Cogan House" name, and says the bridge has also been known by the names of "several tenants who lived in the little farm adjacent" to it.
While Landis does not give these different names, two other names for the bridge are known and may come from some of these tenants. The first of these is "Day's Bridge" and it is clear that this is another name for the Cogan House Covered Bridge.
The second of these, "Plankenhorn Bridge", is a name in a list of existing and vanished covered bridges in Lycoming County. Although the association of this name with the Cogan House Covered Bridge is not made explicitly, it is described as still standing on Larrys Creek and being north of a bridge in Mifflin Township. This is the only known covered bridge that meets those criteria.
History
Background
The first covered bridge in the United States was built over the
Schuylkill River
The Schuylkill River ( , ) is a river running northwest to southeast in eastern Pennsylvania. The river was improved by navigations into the Schuylkill Canal, and several of its tributaries drain major parts of Pennsylvania's Coal Region. It fl ...
in
Philadelphia
Philadelphia, often called Philly, is the largest city in the Commonwealth of Pennsylvania, the sixth-largest city in the U.S., the second-largest city in both the Northeast megalopolis and Mid-Atlantic regions after New York City. Sinc ...
, Pennsylvania in 1800. Some of the first Burr arch truss covered bridges were also built in the state. Pennsylvania is estimated to have once had at least 1,500 covered bridges, and is believed to have had the most in the country between 1830 and 1875.
In 2001 Pennsylvania had more surviving historic covered bridges than any other state, with 221 remaining in 40 of the commonwealth's 67 counties.
Covered bridges were a transition between stone and cast-iron and steel bridges. In 19th-century Pennsylvania, lumber was an abundant resource for bridge construction,
but did not last long when exposed to weather and the elements. The roof and enclosed sides of covered bridges protected the structural elements, allowing some of these bridges to survive well over a century. A Burr arch truss consists of a
load-bearing A load-bearing wall or bearing wall is a wall that is an active structural element of a building, which holds the weight of the elements above it, by conducting its weight to a foundation structure below it.
Load-bearing walls are one of the ea ...
arch
An arch is a vertical curved structure that spans an elevated space and may or may not support the weight above it, or in case of a horizontal arch like an arch dam, the hydrostatic pressure against it.
Arches may be synonymous with vaul ...
sandwiching multiple
King posts, resulting in a bridge which is both stronger and more rigid than one built using either element alone.
In 1850 a
plank road
A plank road is a road composed of wooden planks or puncheon logs. Plank roads were commonly found in the Canadian province of Ontario as well as the Northeast and Midwest of the United States in the first half of the 19th century. They were oft ...
was built in Lycoming County, from the
mouth
In animal anatomy, the mouth, also known as the oral cavity, or in Latin cavum oris, is the opening through which many animals take in food and issue vocal sounds. It is also the cavity lying at the upper end of the alimentary canal, bounded on ...
of Larrys Creek to the borough of
Salladasburg, Pennsylvania
Salladasburg is a borough in Lycoming County, Pennsylvania, United States. The population was 252 at the 2020 census, making it the smallest borough in Lycoming County. It is part of the Williamsport, Pennsylvania Metropolitan Statistical Area.
...
. It was later extended north along the Second Fork of Larrys Creek as far as the unincorporated villages of Brookside and White Pine in Cogan House Township, and eventually went as far as the large
tannery
Tanning may refer to:
*Tanning (leather), treating animal skins to produce leather
*Sun tanning, using the sun to darken pale skin
**Indoor tanning, the use of artificial light in place of the sun
**Sunless tanning, application of a stain or dye t ...
in the village of English Center in
Pine Township on
Little Pine Creek
Little Pine Creek is a tributary of Pine Creek in Lycoming County, Pennsylvania, in the United States. It is approximately long and flows through Pine Township and Cummings Township.
Course
Little Pine Creek begins at the confluence of Texas C ...
. Another branch of the plank road followed Larrys Creek itself north from Salladasburg. While its exact length is unknown, Landis reports it may have reached nearly to the site of the covered bridge.
Before there was a bridge, there was a
ford
Ford commonly refers to:
* Ford Motor Company, an automobile manufacturer founded by Henry Ford
* Ford (crossing), a shallow crossing on a river
Ford may also refer to:
Ford Motor Company
* Henry Ford, founder of the Ford Motor Company
* Ford F ...
at the site where the bridge was later built. Wagons of finished leather and raw hides came from and went to the English Center tannery via White Pine, seeking to avoid traffic on the plank road along the Second Fork. Other traffic went to and from a large sawmill at White Pine and other mills to the west and north. Traffic from the north crossed Larrys Creek, and continued either east over Buckhorn Mountain to the
Williamsport and Elmira Railroad at the village of Cogan Station on
Lycoming Creek
Lycoming Creek is a U.S. Geological Survey. National Hydrography Dataset high-resolution flowline dataThe National Map, accessed August 8, 2011 tributary of the West Branch Susquehanna River located in Tioga and Lycoming counties in Pennsylvan ...
, or south down the road along Larrys Creek. This road led to a tannery on Larrys Creek about south of the ford, and to the plank road along the main branch of the creek. The plank road was a
toll road
A toll road, also known as a turnpike or tollway, is a public or private road (almost always a controlled-access highway in the present day) for which a fee (or ''toll'') is assessed for passage. It is a form of road pricing typically implemented ...
and connected with another railroad, the
West Branch Division of the Pennsylvania Canal, and the
West Branch Susquehanna River
The West Branch Susquehanna River is one of the two principal branches, along with the North Branch, of the Susquehanna River in the Northeastern United States. The North Branch, which rises in upstate New York, is generally regarded as the exte ...
at the creek's mouth.
Because the ford was often impassable in winter or bad weather, or during high water, a petition from the citizens of Cogan House Township for a bridge to be built was filed in September 1876. They asked the county to build the bridge as it was beyond the resources of the township to do so. The petition was read on September 30, 1876, and three viewers were appointed on November 3 to examine the site and report back. The viewers reported back in favor of building the bridge on November 25. On January 23, 1877, the county
grand jury
A grand jury is a jury—a group of citizens—empowered by law to conduct legal proceedings, investigate potential criminal conduct, and determine whether criminal charges should be brought. A grand jury may subpoena physical evidence or a pe ...
approved the report and the construction of the bridge.
Construction and description
![Larrys Creek Covered Bridge Interior](https://upload.wikimedia.org/wikipedia/commons/f/f9/Larrys_Creek_Covered_Bridge_Interior.JPG)
Landis is not certain if the bridge was built in 1877 or 1878, but every other source that mentions the date agrees it was 1877. Valentine ("Tine") Meyers (or Meyer), a
millwright and resident of the hamlet of Quiggleville in
Lycoming Township, built the bridge. The timbers for the bridge were cut at an "up and down",
steam powered
sawmill
A sawmill (saw mill, saw-mill) or lumber mill is a facility where logs are cut into lumber. Modern sawmills use a motorized saw to cut logs lengthwise to make long pieces, and crosswise to length depending on standard or custom sizes (dimensi ...
owned by Robert Wood, a short distance north of the bridge site. The head
sawyer
*A sawyer (occupation) is someone who saws wood.
*Sawyer, a fallen tree stuck on the bottom of a river, where it constitutes a danger to boating.
Places in the United States
Communities
*Sawyer, Kansas
*Sawyer, Kentucky
* Sawyer, Michigan
* Saw ...
at the mill was John Mecum. The wood used was pine, cut in nearby forests and hauled in ox carts to the mill. The largest timbers used in the bridge are up to long.
Meyers is not believed to have had much experience building bridges and set about construction in a unique manner. The timber framework was first assembled in a field next to the sawmill, with each new piece bolted into place after being cut. If a piece did not fit, more careful measurements were made and a new piece was cut and tested. The outlines of the sections for curved beams for the
Burr arch
The Burr Arch Truss—or, simply, Burr Truss or Burr Arch—is a combination of an arch and a ''multiple kingpost'' truss design. It was invented in 1804 by Theodore Burr, patented on April 3, 1817, and used in bridges, usually covered bridge ...
were first marked with chalk on the wood, then the saw crew lifted and guided it by hand against the sawblade to cut the curve. After the framework was completed in the field, it was taken apart, loaded onto the same ox carts used to bring the logs to the mill, and taken to the bridge site. There the framework was reassembled on the bridge
abutment
An abutment is the substructure at the ends of a bridge span or dam supporting its superstructure. Single-span bridges have abutments at each end which provide vertical and lateral support for the span, as well as acting as retaining walls ...
s. Bolts were used to hold all of the large pieces together, while cross-pieces and small braces were nailed in place.
![Cogan House Covered Bridge underside](https://upload.wikimedia.org/wikipedia/commons/c/c3/Cogan_House_Covered_Bridge_underside.jpg)
The Cogan House Covered Bridge was added to the NRHP in 1980 and was listed on the 2009 National Bridge Inventory (NBI). According to the NBI, the covered bridge is long, with a roadway wide, and a maximum load of .
According to the NRHP, the bridge's "road surface width" is , the load is , and the clearance height is .
The width is only sufficient for a single lane of traffic.
As of 2011, the clearance height posted on the bridge itself has been reduced to , and the posted maximum load has been reduced to . According to Landis, the top of the Burr arch is nearly above the floor of the bridge.
The covered bridge rests on the original stone abutments, which have since been reinforced with concrete made of cement. The bridge deck is made of crosswise planking, overlaid with runners in the western half and lengthwise planking in the eastern half. The upper part of the portals and the
clapboard
Clapboard (), also called bevel siding, lap siding, and weatherboard, with regional variation in the definition of these terms, is wooden siding of a building in the form of horizontal boards, often overlapping.
''Clapboard'' in modern Americ ...
siding is made of pine boards, and stops below the roof line.
Although the bridge was painted red as part of its 1998 restoration, in 1964 it was described as unpainted,
and it does not seem to have been painted in 1980, as the NRHP nomination form describes how "its rough horizontal siding ... help
this small bridge blend into the surrounding forest".
The roof was originally covered with wooden shingles.
The bridge does not have
parapet
A parapet is a barrier that is an extension of the wall at the edge of a roof, terrace, balcony, walkway or other structure. The word comes ultimately from the Italian ''parapetto'' (''parare'' 'to cover/defend' and ''petto'' 'chest/breast'). Whe ...
s and has "no steel reinforcements".
[
]
Use and restoration
The Cogan House Covered Bridge was the only one on Larrys Creek to survive a major flood on June 1, 1889, which washed out most other bridges throughout Lycoming County. A large fallen maple tree formed a dam across Larrys Creek, just upstream of the bridge; this dam blocked debris and diverted the brunt of the floodwaters. The same flood destroyed the Larrys Creek plank road and the canal at the creek's mouth. The same storm system also caused the Johnstown Flood
The Johnstown Flood (locally, the Great Flood of 1889) occurred on Friday, May 31, 1889, after the catastrophic failure of the South Fork Dam, located on the south fork of the Little Conemaugh River, upstream of the town of Johnstown, Pennsylv ...
, which killed over 2,200 people.[
''Note:'' ISBN refers to the Heritage Books July 1996 reprint. URL points to a scan of the 1892 edition with some OCR typographical errors.]
After the flood the plank road was only reconstructed as far north as Salladasburg, so for a time all the traffic from the English Center tannery went over the bridge on the way to the railroad at Cogan Station. However, the virgin timber which supplied the local tanneries and sawmills was all clear-cut
Clearcutting, clearfelling or clearcut logging is a forestry/ logging practice in which most or all trees in an area are uniformly cut down. Along with shelterwood and seed tree harvests, it is used by foresters to create certain types of fore ...
within several years of the flood. Without timber, the industries that used the roads leading to the bridge closed and the local villages declined, or, in the case of Buckhorn, disappeared.
By 1900, there were four remaining covered bridges on Larrys Creek: going upstream they were at the hamlet of Larryville in Piatt Township, at or near Mud Run in Mifflin Township, in Salladasburg, and in Cogan House Township. As of 2011, the Cogan House Covered Bridge is the oldest and longest of three 19th-century covered bridges remaining in Lycoming County (the others are the Buttonwood Covered Bridge
The Buttonwood Covered Bridge is a covered bridge built in either 1878 or 1898 over Blockhouse Creek in Jackson Township, Lycoming County in the U.S. state of Pennsylvania. It uses a queen post with king post truss and is long. The bridge was p ...
in Jackson Township over Blockhouse Creek
The Normans Kill is a U.S. Geological Survey. National Hydrography Dataset high-resolution flowline dataThe National Map accessed October 3, 2011 creek in New York's Capital District located in Schenectady and Albany counties. It flows southeast ...
, and the Lairdsville Covered Bridge in Moreland Township over Little Muncy Creek
Little Muncy Creek is the major tributary of Muncy Creek in Lycoming and Sullivan Counties, Pennsylvania, United States. Via Muncy Creek and the West Branch Susquehanna River, it is part of the Susquehanna River drainage basin and waters from i ...
).
The bridge had "needed repairs" made in 1964, and the original stone abutments were reinforced with concrete prior to 1966. It was added to the NRHP on July 24, 1980 in a Multiple Property Submission
The National Register of Historic Places (NRHP) is the United States federal government's official list of districts, sites, buildings, structures and objects deemed worthy of preservation for their historical significance or "great artistic ...
of seven Covered Bridges of Bradford, Sullivan and Lycoming Counties, and was "painted and creosote
Creosote is a category of carbonaceous chemicals formed by the distillation of various tars and pyrolysis of plant-derived material, such as wood or fossil fuel. They are typically used as preservatives or antiseptics.
Some creosote types were ...
d" in 1981. The 1980 NRHP form and Zacher's 1994 book both list the bridge's condition as good. The Lycoming County Commissioners had the bridge "rehabilitated" in 1998, at a cost of $105,493. The general contractor for the restoration was Lycoming Supply Inc., which replaced some structural beams with treated southern pine and the "Dutch lap" or clapboard siding with white pine. The purlin
A purlin (or historically purline, purloyne, purling, perling) is a longitudinal, horizontal, structural member in a roof. In traditional timber framing there are three basic types of purlin: purlin plate, principal purlin, and common purlin.
Pu ...
s and rafter
A rafter is one of a series of sloped structural members such as wooden beams that extend from the ridge or hip to the wall plate, downslope perimeter or eave, and that are designed to support the roof shingles, roof deck and its associated ...
s were reconstructed using treated yellow pine, and support a new roof of cedar
Cedar may refer to:
Trees and plants
*''Cedrus'', common English name cedar, an Old-World genus of coniferous trees in the plant family Pinaceae
*Cedar (plant), a list of trees and plants known as cedar
Places United States
* Cedar, Arizona
* ...
shake shingles. The deck and floor of the bridge were solid and required few repairs. The bridge was painted red, and a stone pillar was built with plaques marking the restoration and the bridge's inclusion on the NRHP.
Because the bridge is listed on the NRHP, the Pennsylvania Historical and Museum Commission
The Pennsylvania Historical and Museum Commission (PHMC) is the governmental agency of the Commonwealth of Pennsylvania responsible for the collection, conservation and interpretation of Pennsylvania's historic heritage. The commission cares for ...
had to approve the renovation. Pennsylvania Department of Transportation
The Pennsylvania Department of Transportation (PennDOT) oversees transportation issues in the Commonwealth of Pennsylvania. The administrator of PennDOT is the Pennsylvania Secretary of Transportation, currently Yassmin Gramian. Presently, Pe ...
(PennDOT) and Federal Highway Administration
The Federal Highway Administration (FHWA) is a division of the United States Department of Transportation that specializes in highway transportation. The agency's major activities are grouped into two programs, the Federal-aid Highway Program a ...
(FHWA) funds helped pay for the work done. The dedication ceremony was held on October 30, 1998, with Lycoming County Commissioner Russell Reitz and PennDOT Director of Municipal Services Thomas Lyons cutting a plank on wooden sawhorses with an old crosscut saw as the ribbon cutting ceremony. The other county commissioners and the local state representative and state senator were also present and spoke, as did a representative of the "Theodore Burr
Theodore Burr (August 16, 1771 – November 22, 1822) was an inventor from Torrington, Connecticut, who was credited with the Burr Arch Truss bridge design. He designed and built one of the first bridges across the Hudson River and several b ...
Covered Bridge Society of Pennsylvania".
In August 2000 an inspection revealed that one of the timber arches of the Cogan House Covered Bridge was damaged by a vehicle which was over the weight limit crossing the bridge. A propane
Propane () is a three-carbon alkane with the molecular formula . It is a gas at standard temperature and pressure, but compressible to a transportable liquid. A by-product of natural gas processing and petroleum refining, it is commonly used a ...
delivery truck making a delivery to the private hunting cabin served by the bridge is thought to have caused the damage. Lycoming Supply Inc. won the bid to do the repair work in December, at a cost of $6,300. Before the repair the bridge remained open and was safe to use. The Evans' 2001 book describes the condition of the bridge as excellent.
Despite the restoration and repairs, the 2009 FHWA National Bridge Inventory
The National Bridge Inventory (NBI) is a database, compiled by the Federal Highway Administration, with information on all bridges and tunnels in the United States that have roads passing above or below them. That is similar to the grade-crossing ...
found the sufficiency rating of the bridge structure to be 17.2 percent. The inventory found the condition of the bridge deck and the substructure was satisfactory, while the superstructure was poor. It further found that the bridge's foundations were "determined to be stable for assessed or calculated scour
Scour may refer to:
Hydrodynamic processes
* Hydrodynamic scour, the removal of sediment such as sand and silt from around an object
* Bridge scour, erosion of soil around at the base of a bridge pier or abutments via the flow of air, ice, or ...
conditions", however the railings "do not meet currently acceptable standards". Its overall condition was deemed "basically intolerable requiring high priority of corrective action"; the 2006 NBI estimated the cost to improve the bridge at $143,000.
The bridge is still used, although the public dirt road to it ends in a cul de sac
A dead end, also known as a cul-de-sac (, from French for 'bag-bottom'), no through road or no exit road, is a street with only one inlet or outlet.
The term "dead end" is understood in all varieties of English, but the official terminology ...
on the east side. A gated private road continues to the private hunting camp and provides access to Pennsylvania State Game Lands The Pennsylvania State Game Lands (SGL) are lands managed by the Pennsylvania Game Commission (PGC) for hunting, trapping, and fishing. These lands, often not usable for farming or development, are donated to the PGC or purchased by the PGC with hun ...
No. 114. The bridge has a posted speed limit of and its average daily traffic was ten vehicles in 2009. ''Pennsylvania's Covered Bridges: A Complete Guide'' notes that despite being "located in a rather remote area, it is worth the trip to see this beautifully restored historic treasure."
Bridge data
The following table is a comparison of published measurements of length, width and load recorded in five different sources using different methods, as well as the name or names cited. The NBI measures bridge length between the "backwalls of abutments" or pavement grooves and the roadway width as "the most restrictive minimum distance between curbs or rails". The NRHP form was prepared by the Pennsylvania Historical and Museum Commission (PHMC), which surveyed county engineers, historical and covered bridge societies, and others for all the covered bridges in the commonwealth. The Evans visited every covered bridge in Pennsylvania in 2001 and measured each bridge's length (portal to portal) and width (at the portal) for their book. The data in Zacher's book was based on a 1991 survey of all covered bridges in Pennsylvania by the PHMC and the Pennsylvania Department of Transportation, aided by local government and private agencies. The article uses primarily the NBI and NRHP data, as they are national programs.
See also
* List of covered bridges on the National Register of Historic Places in Pennsylvania
* List of tributaries of Larrys Creek
Note
:a. The National Highway Administration established the sufficiency rating, which can vary from a low of 0 to a high of 100, as a way to prioritize federal funding for bridges. The rating is calculated for bridges over long, based on "structural adequacy, whether the bridge is functionally obsolete, and level of service provided to the public". Federal funds are available for replacement of bridges with a rating of 50 or below, while those with a rating of 80 or below qualify for rehabilitation. In 2009, Pennsylvania had 22,280 bridges on the NBI, of which 43.8 percent were either structurally deficient (27.2 percent) or functionally obsolete (16.6 percent).
References
External links
*
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Bridges completed in 1877
Bridges in Lycoming County, Pennsylvania
Covered bridges on the National Register of Historic Places in Pennsylvania
Covered bridges in Lycoming County, Pennsylvania
Tourist attractions in Lycoming County, Pennsylvania
Wooden bridges in Pennsylvania
National Register of Historic Places in Lycoming County, Pennsylvania
Road bridges on the National Register of Historic Places in Pennsylvania
Burr Truss bridges in the United States
1877 establishments in Pennsylvania