Sloan Lake (Colorado)

A flock of Canada geese on the frozen surface of Sloan's Lake in winter. The foothills of the Rocky Mountains are in the background.

The true history of the creation of Sloan Lake may never be officially known, but during the settlement of the Denver area in the mid to late 19th century, the lake did not exist. Since spring 1859, South Golden Road connecting Denver and the western suburb of Golden crossed through where Sloan Lake is now.

In December 1866, under the newly enacted Southern Homestead Act, Thomas M. Sloan received a patent for the land from US President Andrew Johnson to use the land for agricultural purposes, farming, and cattle-raising. A commonly accepted and incorrect legend states that Sloan dug a well on the land, inadvertently tapping into an underground aquifer, and that when he awoke the next morning, part of his farm land was covered in water.[3] That flooded this part of South Golden Road, and the realigned thoroughfare, now known as Colfax Avenue would become the major east-west thoroughfare in this part of the city. But, according to gold rush era stagecoach driver Bill Turner, the lake appeared sometime between when he left for Kansas in June 1861 and when he returned in early 1863.[4] It is possible that Sloan occupied the land prior to patenting it. However, its unlikely Sloan would have applied for a patent to farm land that was under water and just as unlikely that the patent would have been granted under the Southern Homestead Act.

The lake once exceeded 200 acres (0.81 km²) and extended north and west beyond its current size, but portions were filled north of 25th Avenue and west of Sheridan Boulevard.[5] The area surrounding the lake was once home to an amusement park and swimming facility known as Manhattan Beach. Opened to the public 27 June 1881, it was the first amusement park to be built west of the Mississippi River (it burned down in 1908 and was rebuilt as Luna Park later that year); mishaps, and competition from other such attractions in the vicinity (Elitch Gardens and Lakeside Amusement Park), led to its closure in 1914. Cooper Lake, a separate body of water just southeast of Sloan's Lake, fell under the jurisdiction of the federal Works Projects Administration in the 1930s, and a plan was developed which involved building channels beneath the surface of the water on both lakes. This essentially created one body of water that has commonly become known as Sloan's Lake. The size of the present-day combined Sloan's Lake and Cooper Lake is 177 acres (0.72 km²).

Sloan's Lake is a seasonal and year-round home to a variety of birds, fish and other wildlife. Birds include white pelicans, mallard ducks, Canada geese, seagulls, barn swallows, house finches, and common night hawks.[6] Cormorants and herons find refuge from shore-based predators in colonies on Cooper Island and feed on black crappie, carp and trout stocked by Colorado Parks and Wildlife agency.[6] The lake’s muddy flats and shallower waters provide habitat for wading birds such as avocets and semi-aquatic rodents including native muskrats and non-native nutria.[6] Predators include fox and coyote, which are occasionally seen around the lake.[7] Cottonwood trees, cattails and bluegrass grow along the shoreline, and the lake waters support duckweed, algae and other native and invasive aquatic plants.[8]

Evening westward view of Penny Island, home to a gamut of waterfowl offspring. The manmade osprey nesting structure is visible near the center of the image.

Found in the center of the lake, Penny Island is a mostly barren 67,396 square foot island. It houses a manmade osprey nesting structure constructed in 2014.[9] The island is a common attraction for local amateur drone pilots.