Visitors may observe mule deer and occasionally bear, as well as porcupine, red fox, pine squirrel, beaver or muskrat at the park. American marten, long-tailed weasel, tiger salamander, striped chorus frog and western terrestrial garter snake are also present.
Over 200 species of migratory and resident birds are known in the park including northern harrier, osprey, great blue herons, western screech-owl, western bluebird, hairy and downy woodpeckers, red-winged blackbird and greater sandhill cranes.
The cutthroat trout population at Pearl Lake is designated as Gold Medal. Brook trout, brown trout and grayling are occasionally reported.
Major native plant communities at Pearl Lake are:
Plant Community Type||
Plant Community Description|
|Sagebrush Shrubland ||Occurs on the northeast side of Pearl Lake and includes big sagebrush, rabbitbrush, hoary sagebrush and other common shrubs.|
|Lodgepole Pine Forest||Common in the park and includes a variety of herbaceous understory species.|
|Northern Subalpine Forest||The most common vegetation in the park along with Lodgepole pine forest, northern subalpine forest can be found on north-facing slopes and includes subalpine fir, Englemann’s spruce and Colorado blue spruce.|
|Aspen Forest ||Includes herbaceous understory species.|
|Willow Carr Wetland||A wetland shrub community made up of a variety of willows including wolf, booth, geyer and shining willow. Shrub, marsh and other wet meadow plant communities can be found around the reservoir, in Beaver Creek and in Lester Creek above and below the dam. |
|Marsh||The most common wetland community at Pearl Lake. Our marshes consist of sedges, rushes, and bulrushes growing in areas of permanent standing water.|
|Wet Meadow||Another type of wetland community found at Pearl Lake. Wet meadow possesses traits suggestive of periodic wet conditions, such as moist soil and hydrophytic vegetation. |
The park is covered by Pleistocene till and Holocene alluvium on the west and north sides. South and east of Pearl Lake are exposures of Precambrian felsic gneiss and volcanic amphibolite.