Mount Jefferson (Montana)

Mount Jefferson
Mt Jefferson and Hollowtop
Highest point
Elevation	10,513 ft (3,204 m)
Prominence	393 ft (120 m)
Coordinates	45°36′10″N 112°00′21″W / 45.60278°N 112.00583°W / 45.60278; -112.00583
Geography
Location	Madison County, Montana, U.S.
Parent range	Tobacco Root
Topo map	USGS Noble Peak, MT
Climbing
Easiest route	Hike

Mount Jefferson is a mountain in the U.S. state of Montana, and is one of the many 10,000+ ft peaks in the Tobacco Root Mountains. The mountain is located in Beaverhead-Deerlodge National Forest. (There is also another Mount Jefferson in Montana, further south, on the Idaho/Montana border.) Hollowtop Mountain is an adjacent, taller peak less than .75 miles (1.2 km) to the north. Over the years, the two summits have had numerous names and elevations recorded on various maps. According to U.S. Geological Survey topographic maps, Mount Jefferson is 10,513 ft (3,204 m), while Hollowtop Mountain to the north is 10,604 ft (3,232 m).

Nomenclature for Mount Jefferson has seen considerable change and confusion over the years. A.N. Winchell, in his 1914 report, Mining Districts of the Dillon Quadrangle, referred to the highest peak in the Tobacco Roots as “Jefferson Peak, locally called Old Hollowtop.” Since that time the more northerly, and higher, of two adjacent peaks has usually been called Hollowtop. This naming convention is easily explained upon viewing the dish-shaped northeasterly-trending glacial cirque that occupies the top of Hollowtop peak. Information is scanty before 1914. Peale (1896) referred to Ward Peak, near Pony, and “unnamed high peaks” in the range. Present local terminology places Ward Peak further south, near McAlister. The idea that Lewis and Clark named the ranges along with the rivers cannot be confirmed.

Some earlier, published maps labeled the northern peak as Mt. Jefferson. Confusion may arise from the fact that the horizontal triangulation control station (VABM) named JEFFERSON is located on the southern peak, and this designation is found on many maps.

In 1933, Tansley and others referred to the high point of the range as Mt. Jefferson, at 10,600 ft. The northern peak was labeled Mt. Jefferson on the Gallatin National Forest map of 1937, with an erroneous (but long-perpetuated) elevation of 10,740’ given. The southern peak was called Hollow Top Mountain, at 10,513’. The next year, 1938, the Deerlodge National Forest map dodged the issue: the northern peak received two designations — Hollowtop Mtn. and Mt. Jefferson. The southern peak was labeled with the JEFFERSON control station only.