Echo Lake was private property surrounded by National Forest lands before it was purchased by Denver in 1920. The natural lake was created in the Late Pleistocene at the base of Goliath Peak when glacial moraine deposits blocked the outlet of the depression in which the lake now lies. The east end of the shallow lake has partially filled with sediments and wetland vegetation; this fen contributes to the lake's hydrologic regime and is considered an important habitat and sensitive area.
One of the early efforts of the Mountain Parks program was to complete the Squaw Pass Road from Bergen Park to Echo Lake. This work required, in the end, the combined efforts and funds of the State of Colorado, the City of Denver, and the USDA Forest Service. It was completed by 1920. In the late 1920s, work continued on the high-altitude road to Summit Lake and the top of Mt. Evans.
Echo Lake Lodge, built in 1926 and added onto the following year, was "octagonal with walls composed of peeled, saddle-notched logs which extend beyond the corners of the building. The roof was low-pitched and featured four dormers and a center stone chimney... the building was planned to provide accommodations to Denver Mountain Park visitors," according to the 1994 National Register nomination. The initial construction of the lodge cost $17,674, and the addition in 1926 cost $10,432. Today it houses a gift shop and restaurant.
In the 1940s, Echo Lake was used for a time as a base for military training at high altitudes. Troops from Buckley Field conducted alpine maneuvers on the treeless slopes of nearby Mt. Evans.