Split Thumb is a glaciated mountain summit located in the

Boundary Ranges The Boundary Ranges, also known in the singular and as the Alaska Boundary Range, are the largest and most northerly subrange of the Coast Mountains. They begin at the Nass River, near the southern end of the Alaska Panhandle in the Canadian p ...

of the

Coast Mountains The Coast Mountains (french: La chaîne Côtière) are a major mountain range in the Pacific Coast Ranges of western North America, extending from southwestern Yukon through the Alaska Panhandle and virtually all of the Coast of British Columbia ...

, 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 sover ...

Alaska Alaska ( ; russian: Аляска, Alyaska; ale, Alax̂sxax̂; ; ems, Alas'kaaq; Yup'ik: ''Alaskaq''; tli, Anáaski) is a state located in the Western United States on the northwest extremity of North America. A semi-exclave of the U.S., ...

. The peak is situated near the southern periphery of the

Juneau Icefield The Juneau Icefield is an ice field located just north of Juneau, Alaska, continuing north through the border with British Columbia, extending through an area of in the Coast Range ranging north to south and east to west. The icefield is the so ...

, northeast of

Juneau The City and Borough of Juneau, more commonly known simply as Juneau ( ; tli, Dzánti K'ihéeni ), is the capital city of the state of Alaska. Located in the Gastineau Channel and the Alaskan panhandle, it is a unified municipality and the se ...

, 2.15 mi (3 km) southeast of

Nugget Mountain Nugget Mountain is a glaciated mountain summit located in the Boundary Ranges of the Coast Mountains, in the U.S. state of Alaska. Location The peak is situated near the southern periphery of the Juneau Icefield, northwest of Split Thumb, ...

, and east of

Heintzleman Ridge Heintzleman Ridge is a elevation mountain ridge located in the Boundary Ranges, in the U.S. state of Alaska. This seven-miles-long ridge, which trends southwest to northeast from Gastineau Channel to Nugget Mountain, is situated north of Juneau, ...

, on land managed by

Tongass National Forest The Tongass National Forest () in Southeast Alaska is the largest U.S. National Forest at . Most of its area is temperate rain forest and is remote enough to be home to many species of endangered and rare flora and fauna. The Tongass, which i ...

. Split Thumb is surrounded by the Lemon Creek Glacier to the west, and Norris Glacier to east. The Split Thumb

Icefall An icefall is a portion of certain glaciers characterized by relatively rapid flow and chaotic crevassed surface, caused in part by gravity. The term ''icefall'' is formed by analogy with the word ''waterfall'', which is a similar phenomenon of t ...

is set on the east aspect of the peak. This peak's descriptive name was published in 1951 by the

U.S. Geological Survey The United States Geological Survey (USGS), formerly simply known as the Geological Survey, is a scientific agency of the United States government. The scientists of the USGS study the landscape of the United States, its natural resources, and ...

. The

first ascent In mountaineering, a first ascent (abbreviated to FA in guide books) is the first successful, documented attainment of the top of a mountain or the first to follow a particular climbing route. First mountain ascents are notable because they en ...

of Split Thumb was made July 2, 1954, by a Juneau Icefield Research Project party comprising

Edward LaChapelle Edward Randle "Ed" LaChapelle (May 31, 1926 – February 1, 2007) was an American avalanche researcher, glaciologist, mountaineer, skier, author, and professor. He was a pioneer in the field of avalanche research and forecasting in North America ...

, Dick Hubley, Carlton Ray, Dr. Conrad Buettner, and Bob Goodwin.

Climate

Based on the

Köppen climate classification The Köppen climate classification is one of the most widely used climate classification systems. It was first published by German-Russian climatologist Wladimir Köppen (1846–1940) in 1884, with several later modifications by Köppen, notabl ...

, Split Thumb is located in a

subarctic climate The subarctic climate (also called subpolar climate, or boreal climate) is a climate with long, cold (often very cold) winters, and short, warm to cool summers. It is found on large landmasses, often away from the moderating effects of an ocean, ge ...

zone, with long, cold, snowy winters, and cool summers. Weather systems coming off the

Gulf of Alaska The Gulf of Alaska (Tlingit: ''Yéil T'ooch’'') is an arm of the Pacific Ocean defined by the curve of the southern coast of Alaska, stretching from the Alaska Peninsula and Kodiak Island in the west to the Alexander Archipelago in the east, ...

are forced upwards by the Coast Mountains (

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 ...

), causing heavy precipitation in the form of rainfall and snowfall. Temperatures can drop below −20 °C with wind chill factors below −30 °C. The month of July offers the most favorable weather to view or climb Split Thumb.

References

Climate

See also

References

External links