The permits that matter most to Idaho river runners all live in the same place: the Four Rivers lottery on Recreation.gov. The Middle Fork of the Salmon, the Wild Main Salmon, the Selway, and Hells Canyon on the Snake River are all allocated through this single system, managed by the U.S. Forest Service. One application window, December 1 through January 31, covers all four. Each river is a separate lottery entry.
These are among the most competitive wilderness river permits in the country. The rivers are genuinely hard to draw, and the competition has only grown. If you're planning a Salmon corridor trip, you need to understand how the system works, what each river requires, and what your options are when the lottery doesn't go your way.
The Four Rivers Lottery
Every application goes through Recreation.gov. The window opens December 1 and closes January 31. Submit one application per river you want to float. Multiple applications for the same river won't help you and may get flagged.
When you apply, you can list multiple preferred launch dates. Pick dates across a wide range rather than clustering around the same week. The Forest Service runs a randomized draw and posts results to your Recreation.gov profile in mid-February. You'll get an email notification, but the results are in your account, not in the email.
If you draw a permit, you have until March 15 to accept and confirm the reservation. Miss that deadline and the date is revoked. On March 16, every unconfirmed and declined date across all four rivers drops back onto Recreation.gov simultaneously, first-come, first-served. Dates go in seconds. This is not an exaggeration. Have your account open and your group details ready before the clock hits 8:00 a.m. Mountain Time.
After that initial March 16 release, in-season cancellations work differently. Recreation.gov releases them at randomized times throughout the day to prevent automated botting. There is no set daily window to watch. A date can surface at 2:00 p.m. on a Tuesday or 9:00 a.m. on a Saturday. That's where monitoring tools earn their keep.
Middle Fork of the Salmon
The run: Boundary Creek to Cache Bar, roughly 100 miles through the Frank Church-River of No Return Wilderness. Class III-IV whitewater. Most groups take 6 to 8 days.
Control season: Late May through early September. The Forest Service allows up to 7 private launches and 3 commercial launches per day, 10 total. Private slots are the bottleneck.
Getting your permit: Win the lottery, accept the reservation by March 15, pay the fee, finalize group details on Recreation.gov. Your actual permit arrives by email from the River Clerk 5 to 6 days before your launch date. That email is the permit. It contains your assigned camps, group size limit, and any applicable special use rules. Update your trip details, including a complete and accurate list of group members, at least seven days before launch or the permit won't issue on time.
Demand: In 2025, July 1 received 733 first-choice lottery applications, the highest of any single date. Early July is the most contested window. Late May and late August draw fewer applicants and give you a real edge.
Cancellations: Permit holders must cancel at least 21 days before their launch date to avoid a late cancellation penalty. A no-show, meaning you fail to launch and never cancelled at all, triggers a three-year ban from holding Middle Fork permits. In-season cancellations surface on Recreation.gov at randomized times. Set a RiverTrip alert for the Middle Fork to get notified the moment a date opens.
Pre/post season: Permits are required year-round. Shoulder season dates (before late May and after early September) are available on a first-come, first-served basis starting October 1 at 8:00 a.m. Mountain Time for the following year. Water can be high in late May, but the crowds are a fraction of peak season.
Read the permit when it arrives. Print a copy and keep a digital backup. Assigned camps vary by date and group size, fire restrictions change year to year, and what's in that document is the source of truth for your trip.
Wild Main Salmon River
The run: Corn Creek to Long Tom Bar, 79 miles through the Frank Church-River of No Return Wilderness. Class III-IV whitewater depending on flows, historically called the River of No Return. The canyon runs over a mile deep for a stretch longer than the Grand Canyon is wide.
Control season: Mid-June through early September. Up to 8 float parties launch per day from the single launch point at Corn Creek.
Getting your permit: Same lottery timeline as the Middle Fork. Results in mid-February, confirmation due by March 15, unconfirmed dates released on March 16. The River Clerk emails the actual permit 5 to 6 days before your launch. Your Recreation.gov reservation is not the permit.
The Main Salmon runs a reservable camp system during control season. A camp request form is emailed to the permit holder about 14 days before launch and must be submitted at least 7 days before launch. Finalize your group details in Recreation.gov before that window, or the permit won't issue on time.
Cancellations: Permit holders must cancel at least 21 days before launch during control season to avoid a late cancellation penalty. A no-show triggers a three-year ban from holding a permit on this river. Outside control season, the minimum cancellation window is three days.
Pre/post season: Shoulder season dates open October 1 on a first-come, first-served basis with no daily launch cap. The period immediately before and after control season can still be congested. Check Recreation.gov to see how many permits have been reserved for any date you're considering before you book.
Selway River
The run: Paradise Launch Site to Race Creek, 47 miles through the Selway-Bitterroot Wilderness. Most groups spend 4 to 6 days on the water. The river drops an average of 28 feet per mile with sustained Class IV whitewater. This is the most technically demanding of the four rivers and the hardest permit to draw.
Control season: Mid-May through late July. The Forest Service allows only one group to launch per day, with a maximum of 16 people. That one-launch-per-day restriction is what makes this the rarest permit in the system.
Getting your permit: Same application window, same March 15 confirmation deadline, same March 16 release of unconfirmed dates as the other three rivers. The Selway runs on identical Recreation.gov mechanics. What's different is attrition: early season permits cancel at a high rate because permit holders bail when flows run dangerously high. If you're committed to the Selway, build a group that can mobilize on short notice. In-season cancellations surface at randomized times throughout the season, same as every other Four Rivers permit.
Post season: No permit is required on the Selway after the control season ends in late July through mid-May the following year. The river typically runs too low for rafts later in the summer, but self-supporting kayak and packraft trips are possible.
Hells Canyon on the Snake River
The run: The Wild and Scenic Snake River through Hells Canyon National Recreation Area on the Idaho-Oregon border. At over 7,900 feet deep, Hells Canyon is North America's deepest river gorge, deeper than the Grand Canyon. Multi-day trips typically run from Hells Canyon Dam to Pittsburg Landing or all the way to Hells Canyon Creek.
Control season: The Friday before Memorial Day through September 10. Reservations are required for non-commercial float parties during this window.
Getting your permit: The same Four Rivers lottery applies. After the control season opens, reservations are available on Recreation.gov starting March 1 at 7:00 a.m. Pacific Time. Private powerboats have a separate reservation process.
Post season: A self-issue permit is available at major launch sites during the secondary season, September 11 through the Thursday before Memorial Day. No lottery required.
Hells Canyon is generally the most accessible of the four permits to obtain, with lower demand relative to the Middle Fork and Selway. If you've been shut out of the other draws repeatedly, it's worth applying here alongside your primary choice.
If You Don't Draw
Most applicants don't draw a permit in any given year. That's not a reason to give up the season.
Catch a cancellation. On March 16, every unconfirmed date across all four rivers hits Recreation.gov at once. Be ready at 8:00 a.m. Mountain Time with your account open. Dates go in seconds, not minutes. After that initial release, in-season cancellations drop at randomized times throughout the day. You won't catch them by checking manually. Set up a RiverTrip alert so you're notified the moment a date opens.
Book shoulder season. Pre- and post-season dates on the Middle Fork and Main Salmon open October 1 with no lottery required. Flows are higher in May and lower in September, but the crowds are gone and the camps are yours to pick.
Apply for Hells Canyon. Lower competition, spectacular canyon, legitimate multi-day wilderness trip. If your group is flexible on destination, this is the most reliable path to an Idaho wilderness float.