Split Thumb

Split Thumb is a 5,523 ft (1,680 m) glaciated mountain summit located in the Boundary Ranges of the Coast Mountains, in the U.S. state of Alaska.^[4] The peak is situated near the southern periphery of the Juneau Icefield, 9 mi (14 km) northeast of Juneau, 2.15 mi (3 km) southeast of Nugget Mountain, and 4 mi (6 km) east of Heintzleman Ridge, on land managed by Tongass National Forest. Split Thumb is surrounded by the Lemon Creek Glacier to the west, and Norris Glacier to east. The Split Thumb Icefall is set on the east aspect of the peak.^[5] This peak's descriptive name was published in 1951 by the U.S. Geological Survey.^[4] The first ascent of Split Thumb was made July 2, 1954, by a Juneau Icefield Research Project party comprising Edward LaChapelle, Dick Hubley, Carlton Ray, Dr. Conrad Buettner, and Bob Goodwin.^[6]

Split Thumb
Split Thumb, south aspect
Highest point
Elevation	5,523 ft (1,683 m)[1]
Prominence	923 ft (281 m)[1]
Parent peak	Mount Wrather[2]
Isolation	2.15 mi (3.46 km)[1]
Coordinates	58°24′23″N 134°18′44″W[1]
Geography
Split Thumb Location in Alaska
Interactive map of Split Thumb
Country	United States
State	Alaska
Borough	Juneau
Protected area	Tongass National Forest
Parent range	Coast Mountains Boundary Ranges Juneau Icefield[1]
Topo map	USGS Juneau B-1
Geology
Rock age	Late Cretaceous
Rock type	Granitic
Volcanic arc	Coast Range Arc
Climbing
First ascent	July 2, 1954
Easiest route	class 5.4 Southeast arête[3]

Climate

Based on the Köppen climate classification, Split Thumb is located in a subarctic climate zone, with long, cold, snowy winters, and cool summers.^[7] Weather systems coming off the Gulf of Alaska are forced upwards by the Coast Mountains (orographic lift), causing heavy precipitation in the form of rainfall and snowfall. Winter temperatures can drop below 0 °F with wind chill factors below −10 °F. The month of July offers the most favorable weather to view or climb Split Thumb.

Gallery

• 
  Looking north at Split Thumb as seen from Observation Peak
• 
  North aspect
• 
  South aspect
• 
  Northeast aspect

See also

• Alaska portal
• Mountains portal

• Geospatial summary of the High Peaks/Summits of the Juneau Icefield
• Geography of Alaska