Frank Church–River of No Return Wilderness, Federal wilderness area in central Idaho, United States

Frank Church–River of No Return Wilderness is a federally protected wilderness area in central Idaho that spreads across the Salmon River Mountains and deep river valleys with many waterways. The terrain covers six national forests and shows rugged mountain slopes, dense woodlands, and wide sections of untouched nature inviting hiking and paddling.

In 1931 the U.S. Forest Service set aside 1,090,000 acres of central Idaho as the Idaho Primitive Area. The Central Idaho Wilderness Act, signed by President Carter on July 23, 1980, combined that area, the Salmon River Breaks Primitive Area and part of the Magruder Corridor into the River of No Return Wilderness, adding 125 miles of the Salmon River to the Wild and Scenic Rivers System. Congress renamed it for Senator Frank Church in 1984; President Reagan signed the measure on March 14, less than four weeks before Church died on April 7 at age 59.

The name "River of No Return" comes from the Salmon River's swift current and large rapids, which make upstream travel difficult. The river is a popular destination for whitewater rafting. In 1968 Senator Frank Church's Wild and Scenic Rivers Act included the Middle Fork of the Salmon, protecting it in free-flowing condition for present and future generations.

The wilderness lies in central Idaho, split by the steep canyons of the Middle and Main forks of the Salmon River. It is separated from the Selway-Bitterroot Wilderness to the north by a single dirt road, the Magruder Corridor. Jetboats are allowed on the Main Fork, and 26 airstrips permit fly-in access, both grandfathered uses from before designation.

The area permits landings at 26 airstrips and the use of motorized boats on the river, two exceptions to usual wilderness protection rules. These allowances have existed since the founding because remote valleys would otherwise be nearly unreachable.