Overview: The Salmon River originates in the Sawtooth and Lemhi Valleys of central and eastern Idaho. Springs and snowmelt from the Sawtooth and Salmon River mountains feed this wild river. The river flows undammed along its 425-mile total length and drains about 14,000 square miles within the borders of Idaho. It is the longest free-flowing river in the lower 48 states. From elevations above 8,000 feet, the Salmon cascades to an elevation of 905 feet before it joins the Snake River in Hells Canyon, near the Idaho/Oregon border. The Salmon River is historically known as The River of No Return. For more than 105 years after the first European Americans came to the area, only one-way trips down the river were possible. The most commonly used boats were wooden scows, designed to carry heavy loads and withstand whitewater. They were then dismantled and used for lumber at the trips' conclusion. It was from these trips that the Salmon's nickname, "River of No Return," originated. Historically, wooden rafts, swimming, cable crossings, bridges or ferries were the only available means by which to cross the River of No Return. Today, there are pack bridges at Stoddard Trailhead, Campbells Ferry, Mackay Bar and Wind River. The Salmon flows through a vast wilderness, as well as the second-deepest gorge on the continent. Only Hells Canyon in the Snake River is deeper. The Salmon's granite-walled canyon is over 1,000 feet deeper than the Grand Canyon. For approximately 180 miles, the Salmon River canyon is more than a mile deep. In the 151 miles from North Fork to Riggins, the Salmon River drops a total of 1,910 feet, or more than 12 feet per mile. Peak flows occur from the middle of May to early July. The river is at its lowest in January and February, but highs and lows are subject to seasonal changes. All boaters floating the wild section of the Salmon River are required to obtain a trip permit before launching at any time of the year. The section of river covered by this system extends from Corn Creek to Long Tom Bar. Boaters floating the South Fork of the Salmon River and exiting onto the wild section of the main Salmon must obtain a tributary permit before floating. South Fork floaters will need to contact the Krassel Ranger District at (208) 634-0616 for permit information. Boating permits are required year-round. Outside the lottery season, the number of launches is unlimited, but a trip permit is required before launching. During the lottery season, a 21-day cancellation is required. Also during the lottery season, the size of the group determines the maximum length of stay. The lottery period for the wild section of the main Salmon extends from June 20 through Sept. 7. During the lottery season, no more than eight float boat parties (commercial and non-commercial) are allowed to launch each day.