The lake is located in a glacial cirque, below Tam McArthur Rim, which was probably last occupied by glacial ice about 13,000 years ago during the Canyon Creek advance of the Cabot Creek glaciation. The outlet stream from the lake flows northward and is joined by two other streams to form Three Creek. The lake is surrounded by old growth forest, and is easy to fish from shore; however, fishing from a boat is the most popular method. The lake elevation is 6,550 feet; it is an alpine gem resting at the base of Tam McArthur Rim south of Sisters. This 28-acre lake has planted rainbow trout and a self-sustaining population of brook trout, ranging from 8 to 15 inches. Most catches average around 10 inches. Trolling flies and lures, fishing from shore, and still-fishing with bait are all successfully used methods.

The shoreline of Three Creek Lake varies from gentle slope to rocky cliff, surrounded by old growth forest. Maximum depth is 28 feet down the center and near the cliff on the south end of the lake. Most of the lake is easy to fish from shore or by wading, but fishing from a boat is by far the most popular method. Motors are not allowed on Three Creek Lake, contributing to the serenity of the setting. There is a primitive boat ramp on the east shore as well as a small store that rents boats.

Motorized boats are prohibited on this body of water. 

There is a primitive boat ramp on east shore near the store.