When you show up at the start of your Middle Fork trip whether it’s Boundary Creek or Indian Creek your eyes will probably land on a massive raft loaded with dry boxes, kitchen supplies, and other gear. Someone always asks the same question: “What is that thing?”
That, my friends is the sweep boat. You won’t find the quiet workhorse of the Middle Fork of the Salmon River anywhere else.
While you’re soaking up sunshine and rapids in a paddle raft, the sweep is already miles ahead, gliding downstream with nearly everything that makes camp life possible: your camp bag, the groover, the kitchen, the fire pan, the tables, and maybe even your favorite beverages.
It’s big. It’s beautiful. And it’s one of the reasons a Middle Fork trip runs so smoothly.
A Brief History
Sweep boats trace their lineage back to the wooden scows once used on the Main Salmon River. In the early days, these large freight boats hauled mining supplies and provisions downriver through rugged canyons. They had sweep arms on both the front and back (much like modern sweep boats) but were so large they required two people to operate.
Because they were too big to row back upstream, crews would disassemble them for lumber at the end of their journey. That’s one origin of the nickname “The River of No Return.”
Today’s sweep boats are the modern descendants of those early workhorses. They are not built from wood, but of durable rubber, steel, and ingenuity. Most commercial outfitters on the Middle Fork run one to carry gear and keep trips moving efficiently.
The Modern Sweep Boat
Modern sweep boats come in all sizes, shapes, and colors, but they share one core purpose: to carry the kitchen, camp gear, and guest bags safely downriver.
At Northwest Rafting Company, our sweep boat is a 22-foot Demaree Inflatable Boat (DIB) bucket raft. A bucket raft has a sealed floor, unlike most modern rafts with self-bailing holes. This design helps the boat ride higher in the water when heavily loaded though it does mean your sweep driver may spend part of the day bailing out water! (Don’t worry our paddle rafts have bail holes, so you won’t have to.)
Before upgrading to a new model in 2023, our previous sweep boat served faithfully for 27 seasons, a testament to both craftsmanship and care.
How Does a Sweep Boat Work?
Sweep boats look a bit unconventional because of their design, which allows them to carry huge loads and still maneuver through the Middle Fork’s technical whitewater.
- High-Volume Tubes: The massive tubes displace tons of water, keeping the boat floating high even when heavily loaded.
- Front and Rear “Sweeps”: Large sweep arms are mounted on the bow and stern. The rear sweep acts like a rudder to hold angle; the front sweep helps steer.
- Elevated Frame: A metal frame sits above the tubes to distribute weight evenly. Nothing rests on the floor of the boat.
- Cowling: The cowling is an elevated frame that sits on top of the tubes, where we rig bags and gear to keep the weight balanced and everything inside the boat secure.
Unlike oar boats, sweep boats don’t have forward propulsion. Their only downstream propulsion is the river’s current, which is why you’ll only see them on the Middle Fork, where continuous flow runs the entire 100 miles.
Voices from the Sweep
No one knows these boats better than the guides who drive them. We asked a few of our sweep boat captains to share what it’s really like behind the sweeps.
How does running a sweep differ from rowing an oar boat?
“Running a sweep boat is different for the obvious reason that the arms go front to back instead of side to side, and because of its size. You’d think such a big boat would be harder to maneuver, especially as the water drops, but the large tubes help it float high through shallow, wide channels and in some of the narrow spots, it’s even easier since I don’t have to ship oars.” – Brodie Sullivan – River guide for 20 years, and driving sweep for 4 years.
What are the biggest challenges of driving sweep?
“Getting it off rocks when you make a mistake and it gets stuck. You generally have to jump out and squat with your legs while you’re in the water pushing with all your might. Then when it finally gets off you have to jump in quickly and get both sweeps in your hands.” – Zach Collier – NWRC owner, River guide for 30 years and driving sweep for 3 seasons (and on and off since then!)
What do you love about driving sweep?
“I love running the sweep because of the feeling of doing it. It’s hard to explain but the way you move your body feels so cool. Standing up on the boat at a slight angle, looking downstream, one arm in front and one in back, moving your feet right to left, jumping up on the cooler or cowling for leverage, arms moving back and forth in unison and then opposite, making in the moment movements and decisions, it’s just magical. Moving the boat becomes second nature. The arms of the sweep become an extension of yourself. Your whole body is involved. You don’t actually think about how to move your body, it just flows, just happens. It’s a dance with the river who is leading and you paired with the sweep boat are one just try to follow without tripping over your own feet. Pure bliss of motion in one of the most beautiful places on the planet. I will always be grateful to have be given the opportunity.” – Audrey Gehlhausen – River guide of 18 years, and drove the sweep boat for 13 of those years
Why Sweep Boats Are So Special
Sweep boats are more than just gear haulers—they’re a symbol of the Middle Fork itself: wild, efficient, and full of character. Watching one glide through a rapid (or thread between boulders with inches to spare) is a sight you won’t forget.
Want to see a sweep boat in action? Join us on a Middle Fork of the Salmon River trip and experience the magic for yourself.
