 Possibilities are many at the Heart Mountain National Antelope Refuge. Located in eastern Lake County, the high desert refuge offers many possibilities, but recent increases in wildlife populations are adding to the allure. Heart Mountain's habitat, which encompasses 278,000 acres, supports a diverse wildlife population, including mostly seasonally nearly 240 bird species, 42 mammals, and a variety of reptiles, including rattlesnakes, bull snakes, and various lizards.