The Thumb is a 13,356-foot-elevation (4,071 meter) mountain summit located on the crest of the Sierra Nevada mountain range, in Inyo County of northern California.[3] It is situated in the Palisades area of the John Muir Wilderness, on land managed by Inyo National Forest. It is 1.3 mile (2.1 km) east of Middle Palisade, 1.6 mile (2.6 km) west-northwest of Birch Mountain, and 1.8 mile (2.9 km) north of Mount Bolton Brown. The Thumb ranks as the 83rd-highest summit in California.[2] Topographic relief is significant as the east aspect rises over 2,500 feet (770 meters) above Birch Lake in approximately one mile. The John Muir Trail traverses below the southwest aspect of the mountain, providing an optional approach access.

The Thumb
East Palisade
The Thumb centered, west aspect
Highest point
Elevation	13,356 ft (4,071 m)[1]
Prominence	594 ft (181 m)[1]
Parent peak	Ed Lane Peak (13,577 ft)[2]
Isolation	0.93 mi (1.50 km)[2]
Listing	Sierra Peaks Section
Coordinates	37°04′17″N 118°26′46″W[3]
Geography
The Thumb Location in California Show map of California The Thumb The Thumb (the United States) Show map of the United States
Location	Inyo County, California, U.S.
Parent range	Sierra Nevada Palisades[1]
Topo map	USGS Split Mountain
Geology
Age of rock	Cretaceous
Mountain type	Fault block
Type of rock	granitic
Climbing
First ascent	1921
Easiest route	class 2[2] Southeast slope

History

The first ascent of the summit was made December 12, 1921, by Windsor B. Putnam via the southeast slope and an approach from Birch Creek. The class 4 northwest face was first climbed June 5, 1930, by Norman Clyde.[4] This mountain's name was submitted for consideration by Windsor B. Putnam, and officially adopted in 1926 by the U.S. Board on Geographic Names.[3] This peak has in the past been called "East Palisade" and "Thumb Peak".[3]

Climate

The Thumb has an alpine climate which supports the Middle Palisade Glacier below the western cliffs.[5] Most weather fronts originate in the Pacific Ocean, and travel east toward the Sierra Nevada mountains. As fronts approach, they are forced upward by the peaks, causing them to drop their moisture in the form of rain or snowfall onto the range (orographic lift). Precipitation runoff from this mountain drains to Owens Valley via Big Pine and Birch Creeks.

Gallery

See also

• List of the major 4000-meter summits of California

References

External links

• Windsor B. Putnam's account of naming and climbing The Thumb: Sierra Club Bulletin
• Weather forecast: The Thumb