Sierra Mac is a widely recognized industry leader, featured in many books and magazines.


Canoe & Kayak - December 2009

The Innovators - People Who Changed the Way You Paddle

MARTY MCDONNELL AND GLENN LEWMAN - Guerillas of the self-bailing revolution

It's easy to take self-bailing rafts for granted, until you don't have one. Anyone who has drifted headlong for a horizon line while frantically tossing buckets of water overboard knows the feeling-pure panic.

Cherry Creek is no place to be in water-logged boat, so it's little wonder that California's landmark Class V run became the birthplace of the n'lodern self-bailing raft. Marty McDonnell began guiding selfbailers on "The Creek" in 1982, nearly a decade after making the first raft descent in the spring of 1973 with Walt Harvest. Later, McDonnell helped develop the revolutionary self-bailers, and his efforts served as the bridge between concept and fruition. McDonnell will be the first to tell you, however, that the evolution started years earlier, with innovator Bryce Whitmore.

Sierra Mac raftWhitmore ran rivers in the 1950s, when the only specialized equipment was homemade. When Whitmore deemed wood and canvas kayaks too cumbersome for the rivers he was running, he built a fiberglass kayak, one of the first in North America. In 1961, he made an exploratory descent of Kings Canyon with paddling icon Roger Paris. When they finished that iconic run, Whitmore got news that his house had burned down. He promptly quit his job as a chemist, and started his own commercial rafting venture.

For rubber, Whitmore used military surplus inflatables originally designed as floating docks for seaplanes. He boldly cut the 24- foot tubes in half and glued them back together, creating a sort of giant air mattress with oars. The boats were crude, but unlike every other river craft of that time, they didn't need bailing.

One of Whitmore's guides in the '60s was McDonnell, who regularly ran different versions of the surplus rafts, known as "Super Sports" and "Huck Finns." By the late '70s, McDonnell was taking the boats down Cherry Creek, and tweaking the designs to better suit the steep riverbed. When a rubber materials supplier began to falter, Marty bought his own bulk neoprene, apprenticed with a lifeboat builder, and started making his own rafts. He strove to create a Huck Finn that you could sit inside of rather than simply riding like a bronco. Despite McDonnell's enthusiasm for design however, raft production wasn't for him. "The novelty of building boats wears off after about the fifth one," he says, "Besides, I wanted to be a user, not a builder." Enter Glenn Lewman-the builder.

Mary McDonnellAs a teenager, Lewman had seen one of Whitmore's original Huck Finns on Oregon's Rogue River. As the boat drifted past, a friend told Lewman, "That's the boat I'd get, because you don't have to bail it." The notion simmered for over a decade before Lewman started SOTAR in 1980, working with McDonnell's feedback, Lewman and the SOTAR team began the inflatable floor experiments.

Their first design included a wooden floor that transformed into a raft-carrying box. It sank. The next incorporated an air mattress attached beneath the wooden floor. It floated, but was brutally heavy. Finally, they scrapped the wood for a lashed-in air mattress. Water coming over raft sides would flow out through the lashings, and the first true self-bailer was born. "From that stage, it took about four more refinements until we got it basically right," Lewman says. Another two years passed before the self-bailing paddle rafts were on the market in '84. Lewman remembers a skepticism that is laughable in hindsight. "People that had never used them had a million reasons why they wouldn't work," he remembers.

A quarter-century later, self-bailing rafts are the industry standard, and rafters rarely experience that feeling of drifting, helplessly, toward a misty horizon. - Tyler Williams; Photo courtesy of Canoe & Kayak


Outside Magazine - September 2007

The Hot List - Urban Survival Guide

Class V rapids on Cherry CreekRaft Class V + rapids on Cherry Creek. The one-day run on the Upper Tuolumne is the hairiest commercially guided whitewater trip in America, dropping an average of 110 feet per mile through slick Sierra bedrock, with 16 Class V rapids packed into just nine miles. The river is so unrelenting (the longest flatwater is a mere 400 yards), clients of Sierra Mac River Trips must undergo a fitness test that includes swimming 140 yards midcurrent and running 70 yards uphill on one breath. Don't fret: In 25 years of commercial trips, no one has died on Cherry Creek. When the excitement ends, stay just outside Yosemite National Park at the 17-room, Gold Rush-era Groveland Hotel (doubles from $145, including break­ fast; - Justin Nyberg


Yosemite Gazette - September 2008

World Class

by Tom Gardner

The term “World Class” has been used many times to describe the Yosemite region: waterfalls, rock-climbing, scenery, geology, and accommodations. Now you can add one more category: white-water rafting.

Yosemite GazetteCourtesy of the Yosemite Gazette

The Tuolumne River, which begins in Yosemite Park, has two sections that offer the best white-water experience in the entire State of California. And nobody knows these rapids better than rafting pioneer Marty McDonnell, outfitter/owner of Sierra Mac River Rafting Trips in Groveland.

Marty’s professional experience began over 45 years ago when he built and sold kayaks out of his parents’ basement. Soon he was guiding for the first commercial rafting company in California. In 1969 Marty led the first professional rafting trip down the Lower Tuolumne, the signature Class IV river experience in California. In 1972 he designed the first self-bailing cataraft and pioneered the Upper Tuolumne/Cherry Creek run, a stretch of river recognized as the most challenging commercially-run whitewater in North America.

Off the Tuolumne, Marty has been a passionate advocate for river conservation and is a founding member of the Tuolumne River Preservation Trust, now serving on its Board of Directors. Sierra Mac River Rafting Trips employs over a dozen highly skilled guides, and one of them is a former member of the national Soviet women’s rafting team. All are exceptional navigators and have advanced certificates in river rescue and wilderness first aid. Read More


Men's Journal - May 2005

100 Greatest Adventures - Whitewater Nation

Cherry Creek/Upper Tuolumne River, California

River printThe most relentlessly white whitewater in North America is nine miles of almost continuous holes, ledges, chutes, and falls — a heart-stopping experience for serious boaters with sharp paddling and swimming skills only. Sierra Mac owner Marty McDonnell did the first descent of Cherry Creek in the early 1970s; he also invented the self-bailing cataraft. You're safe in this guy's hands. - Sarah Friedman


Last River Lost - The Sacrifice of the Stanislaus

"Last River Lost" brings to life the struggle to save the Stanislaus River in the 1970s, then threatened by the Army Corps of Engineers. In Spring 1979, FOR co-director Mark Dubois gained national attention when he put his life on the line to prevent the filling of the New Melones reservoir. His action, and the crash course in activism that the Stanislaus community experienced, left a lasting mark on the environmental movement in the United States and the world. Read More