At a glance: The Salmon River and the Frank Church River of No Return Wilderness

Name: The Salmon River and the Frank Church River of No Return Wilderness.

Size: The Salmon is 425 miles long and the longest completely free-flowing river in the lower 48 states. The wilderness, comprising 2.3 million acres or more than 12,000 square miles, is the largest contiguous wilderness area in the lower 48 states.

Depth: The Salmon River Gorge is more than 6,000 feet deep and is the second-deepest canyon in the nation.

Height: Mountain ranges in the Frank include the Salmon River Mountains and the Bighorn Crags. At least one of the Crags is more than 10,000 feet in elevation.

How The Salmon River got nicknamed “River of No Return”: There is no written indication that explorers Lewis and Clark ever called the river by the nickname. Author Pat Cary Peek attributes the name to a 1935 National Geographic expedition. Some say it was Capt. Harry Guleky of Salmon who dubbed it the River of No Return. In the early 1900s, he would load equipment for miners and homesteaders on big, flat-bottomed boats to make deliveries all the way to Riggins. At the end of his journey, he’d tear the boats apart and sell the lumber because he couldn’t go back up the river. He’d then hop a stagecoach to Salmon and do it all over again. Some believe the name came from the 1954 Marilyn Monroe movie “River of No Return,” which was actually filmed in Canada. Idahoan Bethine Church says the river — and the Frank Church wilderness area — got the name logically: “It’s one of those things that happens from use.”

How to get there:

Wildlife: At least 370 species of wildlife have been identified in the Frank.

History: The Salmon River Canyon has some of Idaho’s oldest known rocks, dating to 1.5 billion years ago.

If you visit: Respect the rules: Pack it in, pack it out. That includes all trash. Leave everything intact. Look all you want, but don’t disturb historical artifacts, rocks and native plants. Minimize campfire impacts. Make small campfires, where permitted and make sure they are completely out and ashes scattered. Respect wildlife. Remember, this is their home, not yours. Never feed the animals. Respect others. Even though you’re out in the wilderness, this is not a place to use your outside voice (unless there’s danger). The Salmon River flows northeast past the town of Salmon, where it is joined by the Lemhi River, then flows northwest and joins the Snake River just south of the Idaho-Oregon-Washington border. The Frank Church River of No Return Wilderness encompasses the Middle Fork of the Salmon River and borders much of the Main Salmon River. It’s connected to the Selway-Bitterroot Wilderness to the north, and the Gospel Hump Wilderness to the northwest. The city of Salmon is one of the best jumping-off points to the Frank.

Key places: