Overview"the mountains are high on either hand leave this gap at the head of this rivulet through which the road passes. here I halted a few minutes and rested myself…. after refreshing ourselves we proceeded on to the top of the dividing ridge from which I discovered immence ranges of high mountains still to the West of us with their tops partially covered with snow. I now decended the mountain about 3/4 of a mile which I found much steeper than on the opposite side, to a handsome bold runing Creek of cold Clear water. here I first tasted the water of the great Columbia river."
This is from the journal of Merriweather Lewis (August 12, 1805)
As Lewis crossed the Continental Divide, he beheld the mountains now known as the Lemhi Range of Idaho. They are as awesome now as they were then, and for the most part as wild and untamed as they were 200 years ago.
Rising out of the Snake River Plain in the south the Lems form a rugged line of peaks stretching N East over 100 miles to end near Salmon Idaho. Unlike the nearby Lost River Range, there are no low passes crossing the Lems. A hundred mile drive may be required to get from one side of the range to the other. Remote, unpopulated, rugged, beautiful, all these words describe the Lems.
You will find few, if any, people in the back country. Odds are great that you will find youself alone on any peak you choose to climb, even the highest point in the range - Diamond Peak at 12,197 feet.
High and dry in the south, lower and greener in the north describes this range, with dozens of peaks beckoning as you travel north. Saddle Mountain, Diamond Peak, Bell Mountain, Gilmore, Big Creek, Yellow and Lem Peaks, to name a few. A sub range to the west holds Bear Mountain and Iron Creek Point on the Iron Divide.
From the the main Lemhi divide look west and behold the entire length of the Lost River Range. Look east to gaze upon the Beaverheads. The views are exceptional. One of the great high ranges of Idaho, a trip to this area will be a memorable one!
GeologyThe Lemhi range contains complex geology, rich mineral deposits. The Lems (along with the the Beaverheads) are a Basin and Range formation.
Much of the range is underlain by Mesoproterozoic strata of the Belt Supergroup, deposited between 1470 and 1370 million years ago, and make up most of the northern Lemhi and Beaverhead Ranges. Paleozoic sedimentary rocks are exposed in the southern part of the range, and are mainly limestones.
Eocene volcanic rocks of the Challis volcanic group are found along the north and west edge of the range, and are cut by northeast striking faults of the Trans-Challis fault system.
The western boundary of the Lemhi Range is the active Lemhi Fault. Just northeast of Howe near South Creek is a block of Paleozoic rocks that slid southwest from the Lemhi Range into the Little Lost River Valley.
Much of the mid-section of this range was mined for copper, lead, silver and some gold. Evidence of this activity, which took place in the early 1900's, can still easily be found, especially near the Gilmore summit.