[1][2][3] The water in Hart Lake is quite murky due to suspended particles stirred up from the shallow bottom by wave action.

[9][10][11] Hart Lake's native fish species include the Warner sucker, tui chub, and Great Basin redband trout.

In addition to the native fish, rainbow trout, crappie, smallmouth bass, and bullhead catfish have been introduced into the lake.

A 1996 fish survey estimated the total population of adult Warner suckers resident in Hart Lake at only 493 individuals.

Mammals common in the Hart Lake shoreline and marshes include raccoons, striped skunks, and muskrats.

[11] Species that nest near the lake include sandhill cranes, American white pelicans, double-crested cormorants, willets, Wilson's phalaropes, gadwalls, northern shovelers, American coots, western grebes, Clark's grebes, black-crowned night herons, Canada geese, mallards, and numerous other varieties of ducks and terns.

[9][10][11] Just north of Hart Lake, at the Warner Wetlands Interpretive Site, there are bird observation blinds maintained by the Bureau of Land Management where American bitterns, black-necked stilts, cinnamon teal, tundra swans, Brewer's blackbirds, western meadowlarks, nighthawks, and several swallow varieties are commonly observed.

[10][11][19] Native Americans used the Warner Valley's lakes and wetlands for thousands of years before the first white explorers arrived.

The Greaser Petroglyph Site, approximately 3 miles (5 km) southeast of Hart Lake, is listed on the National Register of Historic Places.

[2][21] In 1867, General George Crook decided to build a fort in the Warner Valley to prevent Indian raiding parties from passing through the area.

[25][26] Later in the 19th century, much of the private land near Hart Lake was acquired by physician Bernard Daly and became part of his "7T Ranch".

[1][3] In the late 1980s and early 1990s, the Warner Valley experienced an extended drought, reducing the water in Hart Lake to a dangerously low level.

Before the lake water had disappeared, the Fish and Wildlife Service captured a number of Warner suckers for temporary relocation.

In addition, the land along the east shore is part of the Hart Mountain National Antelope Refuge, which is managed by the United States Fish and Wildlife Service.

These public lands offer numerous recreational opportunities such as hunting, fishing, bird watching, boating, and camping.

There are also public restrooms, sheltered picnic tables, and hiking trails at the Warner Wetlands Interpretive Site, north of Hart Lake.