State Route 166 (SR 166) is part of

Maine Maine () is a state in the New England and Northeastern regions of the United States. It borders New Hampshire to the west, the Gulf of Maine to the southeast, and the Canadian provinces of New Brunswick and Quebec to the northeast and north ...

's system of numbered

state highways A state highway, state road, or state route (and the equivalent provincial highway, provincial road, or provincial route) is usually a road that is either ''numbered'' or ''maintained'' by a sub-national state or province. A road numbered by a ...

, located in the southern coastal part of the state adjacent to the mouth of the

Penobscot River The Penobscot River (Abenaki: ''Pαnawάhpskewtəkʷ'') is a U.S. Geological Survey. National Hydrography Dataset high-resolution flowline dataThe National Map, accessed June 22, 2011 river in the U.S. state of Maine. Including the river's We ...

. It runs just under between the town of Castine and Orland at

U.S. Route 1 U.S. Route 1 or U.S. Highway 1 (US 1) is a major north–south United States Numbered Highway that serves the East Coast of the United States. It runs from Key West, Florida, north to Fort Kent, Maine, at the Canadian border, making i ...

(US 1) and SR 3/ SR 15.

Route description

The southern terminus of SR 166 is located at the intersection of Battle Avenue and Main Street in Castine, near the

Maine Maritime Academy Maine Maritime Academy (Maine Maritime or MMA) is a public college focused on maritime training and located in Castine, Maine. The academy was established by the 90th Maine Legislature on March 21, 1941. Unlike federal service academies, a congr ...

main campus. Battle Avenue carries the initial stretch before turning northward as Castine Road as the route exits the downtown area. SR 166A splits off just to the northeast towards the

Bagaduce River The Bagaduce River is a tidal river in the Hancock County, Maine that empties into Penobscot Bay near the town of Castine. From the confluence of Black Brook and the outflow of Walker Pond (), the river runs about U.S. Geological Survey. Nationa ...

to the east. SR 166 turns to the northwest at this point to run closer to the Penobscot River along The Shore Road. This portion of the road heads north through the settlement of West Castine passing some small houses along the way. Continuing north, intersecting the northern end of the SR 166A half-loop at Morse Cove. Now in the town of

Penobscot The Penobscot (Abenaki: ''Pαnawάhpskewi'') are an Indigenous people in North America from the Northeastern Woodlands region. They are organized as a federally recognized tribe in Maine and as a First Nations band government in the Atlantic pr ...

and following Castine Road again, SR 166 parallels the river even closer and reaches the terminus of SR 175 at the settlement of West Penobscot. North of SR 175, the road ends paralleling the Penobscot River but begins following the route of the

Orland River The Orland River is a U.S. Geological Survey. National Hydrography Dataset high-resolution flowline dataThe National Map, accessed June 22, 2011 river in the town of Orland in Hancock County, Maine. It is part of the Penobscot River watershed. ...

at South Orland within the town of Orland. Past here, SR 166 heads into a less populated stretch of land, mostly in wooded areas. As the road comes closer to the center of the town, the number of houses lining the road increases. SR 166 curves to the west at Old Country Road and crosses the Orland River on a small bridge. Now in the business district of the town, SR 166 passes small markets, boating shops, and a post office a peninsula known as Leaches Point. After passing a few more houses, Castine Road and SR 166 ends at a stop-controlled intersection with Acadia Highway (carrying US 1, SR 3, and SR 15).

History

Modern SR 166, as first designated in 1939, actually existed as two separate split routes—SR 166W and SR 166E. State Route 166E was a renumbering of State Route 202, which was first designated in 1925. When US 202 was designated in Maine in 1934, it became a duplicate numbering but was not renumbered until 1939. SR 166E was the longer of the two split routes, serving Castine to the south and connecting with SR 175 to the north. This designation only lasted until 1941, when SR 166E, SR 175 and SR 199 underwent routing changes. The remaining length of SR 166E was renumbered as SR 166. State Route 166W was a newly designated half-loop routing along the western side of the peninsula, and persisted even after SR 166E was renumbered. This route was eventually renumbered SR 166A in 1947. Throughout most of its history, SR 166 ran along the west side of the peninsula in Castine (with an intersection at SR 199) and ended at SR 175. SR 175 continued north along Castine Road through Orland. In August 2014, a

Maine Department of Transportation The Maine Department of Transportation, also known as MaineDOT (occasionally referred to as MDOT), is the office of state government charged with the regulation and maintenance of roads, rail, ferries, and other public transport infrastructure in ...

official proposed swapping the designations of SR 166 and SR 166A as the western route was the most direct route into Castine and the extension of SR 166 to Orland to prevent travelers from following multiple route numbers from US 1 to Castine. Both changes were implemented by June 2015.

Pre-renumbering (1925-36)

The first highway in Maine numbered 166 was located in the northeastern part of the state. It was designated in 1925 and ran between Magadahoc and Houlton. In 1936, the entire route was redesignated as US 2A.Floodgap Roadgap's RoadsAroundME: Maine State Route 166
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Junction list

State Route 166A

State Route 166A, also known as Castine Road, is a town-maintained

alternate route An official alternate route is a special route in the United States that provides an alternate alignment for a highway. They are loop roads and found in many road systems in the United States including the U.S. Highway system and various state an ...

of SR 166 in Castine, running on the eastern side of the peninsula. It forms a half-loop and connects with its parent at both ends. The route originally ran along the west side of the peninsula on The Shore Road. It was first designated in 1939 as SR 166W and what became SR 166 was designated SR 166E. After reorganization of several routes in 1940, SR 166E was redesignated as SR 166 proper. SR 166W retained its designation until 1947, when it was renumbered to 166A. SR 166 and SR 166A were swapped between 2014 and 2015 to improve traveler access to the downtown area of Castine. SR 166A begins at an intersection with SR 166 in Castine, north of its downtown. It generally heads northeast near the

heading past small houses and undeveloped areas consisting of forests and brush. After passing through the settlement of North Castine, it intersects SR 199 at its southern terminus. The road then heads north through a more wooded area. The town line between Castine and Penobscot begins to run down the road and does so for the remainder of its route. SR 166A ends at SR 166 at Morse Cove. ;Junction list

References