The section of the Salmon River extending from Corn Creek to Carey Creek is commonly referred to as the Main Salmon, and it picks up approximately 5 miles below Cache Bar, the take-out for the Middle Fork of the Salmon. Downstream of this Main Salmon stretch boaters will find several popular day floats and a longer multi-day float commonly known as the Lower Main Salmon. The Main Salmon stretch is approximately 80 miles long, and it is often floated in six days. Private boaters float alongside commercial outfitters, and rafters share the river with generally courteous jet boaters (a legacy entitlement from before the implementation of the Central Idaho Wilderness Act of 1980).
Along the way boaters will have the opportunity to see some of the country’s most beautiful river canyon scenery, raft exciting whitewater, delve into a rich culture of early river runners and homesteaders, soak in hot springs, hike side trails, ponder pictographs, peer up steep canyon walls, and enjoy views of the campfire and stars from broad beach campsites. The Main is frequently compared to the Middle Fork, and the two trips do have different characteristics, but it is worth noting from the outset that both are magnificent ways to spend your river time, and both provide pristine wilderness experiences from within deep canyons that you’ll never forget.
Most note that the Main is a better choice for families, and this is a fair assessment given the river’s character and climate (depending on the family, of course). Being downstream means it receives more tributaries and carries more water, which also means that its gradient isn’t as steep. The Middle Fork averages 28 feet per mile; in contrast, the Main averages 12 feet per mile. The most challenging rapids on this stretch still range from Class III+ to Class IV at normal flows, though they can be more straightforward and more forgiving than those on the Middle Fork. Large pools and long stretches of lazy water separate the rapids, and these sections are ideal for cooling off in the summer heat that bakes the canyons. In terms of elevation, the Corn Creek launch sits at 2,920 feet, significantly lower than Middle Fork’s Boundary Creek put-in that sits at nearly 5,700 feet. Air and water temperatures are considerably warmer on the Main, which can translate to long days beneath the summer sun and delicious nights beneath the stars. Larger flows and warmer weather also extend the floating season on this stretch well beyond the lottery dates.
Boaters floating through this 40-million-year-old canyon will be experiencing one of the country’s deepest. The granite that forms the massive canyon walls and idiosyncratic shapes is part of the Idaho Batholith and is approximately 65 million years old. The earliest signs of human habitation in this area are approximately 12,000 years old. The Shoshone and Nez Perce lived in the area prior to the arrival of white settlers, and their pictographs can be found at several points along the river. The Main also has an abundance of homesteads, cabins, and defunct mining operations left behind by the settlers to this area. The history and culture of this river runs deep, and visitors will have plenty of opportunities to appreciate the lives these early residents led. It is vital to respect these areas and leave them untouched and undamaged. As with your river practice in general, please leave no trace.
Wildlife along the Salmon River includes large game such as black bear, elk, white-tailed deer, mountain lions, and bighorn sheep. Foxes, coyotes, porcupines, and beavers are among the smaller mammals, and chukars are common along the rocky banks. Fishing on the Main varies greatly depending on the season and the water temperature: Rainbow, cutthroat, and bull trout come alive in the cooler weather, while warm-water fish like bass are a better bet in the summer heat. Runs of Chinook salmon and steelhead have made this river a favorite among fishers, especially in the fall when fishing and hunting trips can be combined.
There are many rapids on this section that are Class II and above. Below is a list of rapids considered Class III-IV at normal flows.
While some sections of the Salmon River may be floated by private boaters without a permit, both the Middle Fork of the Salmon and the section of the Main Salmon from Corn Creek to Long Tom Bar (above the Carey Creek take-out) require permits. The Forest Service uses the Four Rivers Lottery and Permit Reservation System to issue permits for the Selway, the Snake, the Middle Fork, and the Main Salmon. Applications for this lottery can be submitted between December 1 and January 31; for the Main Salmon, the lottery applies for trips run from June 20 through September 7. Boaters floating the Main Salmon outside of these dates can start reserving their dates on October 1 at the Recreation.gov site used for pre- and post-season applications.
All boaters need to practice Leave No Trace principles at all times. Fire pans and ash containers are required along with portable toilet systems and food strainers. Given the high number of visitors this river corridor receives, responsible recreation and stewardship here is a must.
Campsite selection on the Main Salmon would be considerably more efficient if it were managed online in the same manner as the permits. Instead the system relies upon a large board that is posted at the Corn Creek Ranger Station; this board lists a schedule of available and occupied reservable campsites. Once boaters have a sense of which campsites will be available during their float (taking into account the pace of boaters who are already on the water), boaters can post a wish list of campsites on the board the night before they launch. The permit holder then meets with the rangers and other permit holders on the morning of launch day for campground assignments. With any luck, posting the wish list the night before will circumvent conflicts over camp selection (or facilitate some bargaining).
The Corn Creek Campground just upstream from the boat ramp has 17 first-come, first-served sites. Potable water is available.
The Main Salmon is floatable year round, though flows can become dangerously high during the spring runoff, and weather can become miserably cold in the winter. Unlike the Middle Fork, however, the water does stick around through late summer and fall. Boating this river above 6.5 feet on the Corn Creek gage is extremely hazardous.
Average summer temperatures can be quite warm on the Main Salmon, and days that stretch into the 90s and beyond are not uncommon; warm evenings around camp on the large river beaches can be a welcome respite from the scorching sun. Storm systems are common, however, so be sure to bring insulating layers and rain gear in addition to your sun protection. Shoulder season temperatures can mean highs in the 50s and 60s and lows approaching freezing. Ice flows develop on the river in the winter, but it is still possible to float on certain stretches for the highly dedicated.