Harriman State Park is a public recreation area situated on the 11,000-acre (4,500 ha) Harriman Wildlife Refuge[2] in Fremont County, located three miles (4.8 km) south of Island Park in eastern Idaho, United States.

The state park is located within the Henry's Fork Caldera, which is part of the Greater Yellowstone Ecosystem.

It serves as a habitat for various wildlife, including elk, moose, sandhill cranes, trumpeter swans, and the occasional black or grizzly bear.

[4] The park's acreage was owned by Union Pacific Railroad investors from 1902 to 1977, serving as a cattle ranch and private retreat for the Harriman and Guggenheim families.

[6] Henrys Fork, a fly-fishing stream of note, winds through park meadows for eight miles.