[1] It is fed primarily by the Murtle River which rises from a large unnamed glacier in the Cariboo Mountains at an elevation of 2,300 m (7,546 ft) and flows southwest for 18 km (11 mi) to the lake.

In 1968, about 40% of Wells Gray Park or 525,680 acres (212,735 ha) was set aside as the Murtle Lake Nature Conservancy and gave this area a high level of protection from development.

[2][3]: 182 Following is the first written description of Murtle Lake, taken from Joseph Hunter's diary: "From the head of the canyon [at McDougall Falls] to Camp 10, 2 1/2 miles...the river is from 175 to 200 feet wide.

I soon discovered that we had crossed an arm of this (Murtle Lake) early in the morning...It is enclosed on the east by low green hills; on the north the mountains are bold, high and rugged.

On the south, the most important in case a line of railway should come this way, the mountains are steep but not rough, and generally keep well away from the lake, leaving a margin of hard, firm, level ground along the shore.

Between 1872 and 1881, about 20 survey parties fanned out across British Columbia trying to find the best route for the new railway between Yellowhead Pass in the Rocky Mountains and the Pacific Coast.

When the more southern Kicking Horse Pass was chosen instead in 1881, all of these meticulously examined routes across the Canadian Cordilleran, including Hunter's, were abandoned.