Bonanza Peak is a tall peak in the

North Cascades The North Cascades are a section of the Cascade Range of western North America. They span the border between the Canadian province of British Columbia and the U.S. state of Washington and are officially named in the U.S. and Canada as the Casca ...

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 ...

Washington Washington commonly refers to: * Washington (state), United States * Washington, D.C., the capital of the United States ** A metonym for the federal government of the United States ** Washington metropolitan area, the metropolitan area centered o ...

and the

Glacier Peak Wilderness Glacier Peak Wilderness is a , , wilderness area located within portions of Chelan, Snohomish, and Skagit counties in the North Cascades of Washington. The area lies within parts of Wenatchee National Forest and Mount Baker National Forest ...

of the

Wenatchee National Forest Wenatchee National Forest is a U.S. National Forest located in Washington (state), Washington. With an area of 1,735,394 acres (2,711.55 sq mi, or 7,022.89 km²), it extends about 137 miles along the eastern slopes of the Cascade Range of Wa ...

. At in elevation, it is the highest point in Chelan County, and the highest non-volcanic peak in Washington and the Cascade Range as a whole. Bonanza Peak's

prominence In topography, prominence (also referred to as autonomous height, relative height, and shoulder drop in US English, and drop or relative height in British English) measures the height of a mountain or hill's summit relative to the lowest contou ...

is , making it the 26th most prominent peak in Washington. The nearest higher peak is

Glacier Peak Glacier Peak or Dakobed (known in the Sauk-Suiattle dialect of the Lushootseed language as "Tda-ko-buh-ba" or "Takobia") is the most isolated of the five major stratovolcanoes (composite volcanoes) of the Cascade Volcanic Arc in the U.S state ...

, to the southwest. Bonanza Peak is flanked with three large glaciers: Company Glacier to the north, Mary Green Glacier to the east, and Isella Glacier to the south.USGS topographic maps accessed from USGS

GNIS The Geographic Names Information System (GNIS) is a database of name and locative information about more than two million physical and cultural features throughout the United States and its territories, Antarctica, and the associated states of ...

website

History

Bonanza Peak was originally named North Star Mountain, with a minor mountain to the southwest given the name Bonanza Peak. The USGS’ first topographic map of the region in 1904, however, mistakenly interchanged the names and the USGS naming was retained. Bonanza Peak was first summited in 1937 by Curtis I. James, Barrie James, and Joe Leuthold, all members of the

Mazamas The Mazamas () is a mountaineering organization based in Portland, Oregon, United States, founded in 1894. Promotion of mountaineering The Mazamas has been an important part of the climbing community in the Pacific Northwest of the United States ...

Climate

Lying east of the Cascade crest, the area around Bonanza Peak is a bit drier than areas to the west. Summers can bring warm temperatures and occasional thunderstorms. Most

weather front A weather front is a boundary separating air masses for which several characteristics differ, such as air density, wind, temperature, and humidity. Disturbed and unstable weather due to these differences often arises along the boundary. For in ...

s originate in the

Pacific Ocean The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the contin ...

, and travel northeast toward the

Cascade Mountains The Cascade Range or Cascades is a major mountain range of western North America, extending from southern British Columbia through Washington and Oregon to Northern California. It includes both non-volcanic mountains, such as the North Cascades, a ...

. As fronts approach the

, they are forced upward by the peaks of the Cascade Range, causing them to drop their moisture in the form of rain or snowfall onto the Cascades (

Orographic lift Orographic lift occurs when an air mass is forced from a low elevation to a higher elevation as it moves over rising terrain. As the air mass gains altitude it quickly cools down adiabatically, which can raise the relative humidity to 100% and cr ...

). As a result, the North Cascades experiences high precipitation, especially during the winter months in the form of snowfall.Beckey, Fred W. Cascade Alpine Guide, Climbing and High Routes. Seattle, WA: Mountaineers Books, 2008. Precipitation

runoff Runoff, run-off or RUNOFF may refer to: * RUNOFF, the first computer text-formatting program * Runoff or run-off, another name for bleed, printing that lies beyond the edges to which a printed sheet is trimmed * Runoff or run-off, a stock marke ...

from the mountain and meltwater from its glaciers drains to nearby

Lake Chelan Lake Chelan ( ) is a narrow, long lake in Chelan County, north-central Washington state, U.S. Before 1927, it was the largest natural lake in the state by any measure. Upon the completion of Lake Chelan Dam in 1927, the elevation of the lake w ...

via Agnes, Company, and Railroad Creeks,

Geology

The North Cascades features some of the most rugged topography in the Cascade Range with craggy peaks, ridges, and deep

glacial valley U-shaped valleys, also called trough valleys or glacial troughs, are formed by the process of glaciation. They are characteristic of mountain glaciation in particular. They have a characteristic U shape in cross-section, with steep, straight s ...

s. Geological events occurring many years ago created the diverse topography and drastic elevation changes over the Cascade Range leading to the various climate differences. These climate differences lead to vegetation variety defining the

ecoregion An ecoregion (ecological region) or ecozone (ecological zone) is an ecologically and geographically defined area that is smaller than a bioregion, which in turn is smaller than a biogeographic realm. Ecoregions cover relatively large areas of ...

s in this area. The history of the formation of the Cascade Mountains dates back millions of years ago to the late

Eocene The Eocene ( ) Epoch is a geological epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period in the modern Cenozoic Era. The name ''Eocene'' comes from the Ancient Greek (''ēṓs'', " ...

Epoch. With the

North American Plate The North American Plate is a tectonic plate covering most of North America, Cuba, the Bahamas, extreme northeastern Asia, and parts of Iceland and the Azores. With an area of , it is the Earth's second largest tectonic plate, behind the Pacif ...

overriding the Pacific Plate, episodes of volcanic igneous activity persisted.

, a stratovolcano that is southwest of Bonanza Peak, began forming in the mid-Pleistocene.Beckey, Fred W. Cascade Alpine Guide, Climbing and High Routes. Seattle, WA: Mountaineers Books, 2008. In addition, small fragments of the

oceanic Oceanic may refer to: *Of or relating to the ocean *Of or relating to Oceania **Oceanic climate **Oceanic languages **Oceanic person or people, also called "Pacific Islander(s)" Places * Oceanic, British Columbia, a settlement on Smith Island, ...

and

continental lithosphere A lithosphere () is the rigid, outermost rocky shell of a terrestrial planet or natural satellite. On Earth, it is composed of the crust and the portion of the upper mantle that behaves elastically on time scales of up to thousands of years or ...

called

terrane In geology, a terrane (; in full, a tectonostratigraphic terrane) is a crust (geology), crust fragment formed on a tectonic plate (or broken off from it) and Accretion (geology), accreted or "Suture (geology), sutured" to crust lying on another pla ...

s created the

about 50 million years ago. During the

Pleistocene The Pleistocene ( , often referred to as the ''Ice age'') is the geological epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was finally confirmed in ...

period dating back over two million years ago, glaciation advancing and retreating repeatedly scoured the landscape leaving deposits of rock debris. The "U"-shaped cross section of the river valleys are a result of recent glaciation. Uplift and faulting in combination with glaciation have been the dominant processes which have created the tall peaks and deep valleys of the North Cascades area.

Gallery

File:Bonanza Peak from the trail between Lower and Upper Lyman Lake.jpg, Bonanza from Lyman Lakes area File:Plummer Mountain vista.jpg, Bonanza and North Star Mountain, from Plummer Mountain

References

External links