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Sierra Mac River Trips

Tuolumne's First Outfitter

Contact Us BOOK NOW 209.591.8027

About Sierra Mac River Trips

Sierra Mac guide crew in 1972

Marty McDonnell, Sierra Mac River TripsOutfitter-Owner, Marty McDonnell
Built and sold kayaks in the 60s. Designed the first self-bailing cataraft. Pioneered rafting trips on the Cherry Creek/Upper Tuolumne run in 1973, still considered the most challenging commercial river trip in US. Developed operational standards for guides and outfitters in California with the US Forest Service. Operated the first gourmet river expeditions with Chef Armando Dominguez. Founding board member of the Tuolumne River Trust and the Clavey River Coalition since 1982.

River Expertise: Professional guide since 1965 • Guide Class: Class IV (V+ Retired)

Rivers Professionally Navigated: California—Cherry Creek, Main Tuolumne, Stanislaus Camp 9, Merced, Klamath, Eel; Elsewhere—Grand Canyon (Arizona), Rogue (Oregon), Columbia (Canada), Apurimac and Urubamba (Peru), Ruhr (Germany), Eyre (France)

Home Base: Groveland, California (Vacaville)

Since 1965, we at Sierra Mac River Rafting Trips have dedicated ourselves to providing exceptionally fine whitewater river trips. We operate exclusively on the rivers that flow from Yosemite National Park, both the Merced and Tuolumne Rivers have been bestowed with “Wild and Scenic” status by the US Congress for their outstanding whitewater and superb scenery. The Tuolumne’s classic class IV run from Meral’s Pool to Ward’s Ferry is excellent for first time boaters and veteran river runners alike. The Cherry Creek/Upper Tuolumne is for serious boaters looking for the ultimate challenge. Expert guides, state of the art self-bailing rafts, plentiful and delicious meals, and meticulous, behind-the-scenes planning is our hallmark. You won’t find a crew with more years on the water and better credentials than Sierra Mac.

My great love for rivers and whitewater navigation began at an early age and spans over 45 years. In my teens I built and sold kayaks out of my parents’ basement and guided for the first commercial rafting company in California. In 1969 I led the inaugural professional rafting trip down the Main Tuolumne, a run that quickly became the classic Class IV river experience in California. In 1972 I designed the first self-bailing cataraft and used it to pioneer the Cherry Creek/Upper Tuolumne run, a stretch of river recognized as the most challenging commercially-run whitewater in the U.S.

Off the river, I have been a passionate advocate for river conservation and environmental causes my whole life. As one of the charter members of the board of the Tuolumne River Trust (www.tuolumne.org), we led the successful campaign to stop numerous destructive dam projects on the Tuolumne and its tributaries, preserving this rare piece of Sierran wilderness for generations to come. After 38 years, I still immensely enjoy rafting the “T”. I personally oversee general operations and each reservation on the Tuolumne River and Cherry Creek to ensure a seamless vacation experience.

It is a privilege to host first-time boaters and veterans alike on our favorite river canyon. Nothing takes you farther away from your routines than a splash of white water and the tranquility of a wilderness river canyon. We look forward to sharing our love for this place and the magic of whitewater with you. Let’s go rafting!

Marty McDonnell, Sierra Mac River Rafting Trips

TOM McDONNELLSierra Mac whitewater rafting guide Tom McDonnell
Outfitter-Owner Lead Guide,

Ultimate Frisbee, Skiing, Surfing, Social Media, Gamer
Professional guide since 2004 • Guide Class: V+
Rivers Professionally  Navigated: California – Cherry Creek, Tuolumne, Merced, Kings; Elsewhere – Rio Azul, Futaleufú (Chile); Pecuare, Sevengre, Coto Brus (Costa Rica); Grand Canyon of the Colorado (Arizona), Zambezi (Zambia)
Off-Season Employment: Sierra Mac R+D
Home Base: Colfax Spring, CA

Ultimate Frisbee, Skiing, Surfing, Social Media, Gamer, soon to be Father!

Why Choose
Sierra Mac?

Why Us
Our History
Experienced Guides
Closest To Yosemite
Rave Reviews
Preserving Rivers

Rafting Trips

Cherry Creek / Upper T
Main Tuolumne
Combination Trip
Merced River
Yosemite Float Trip
Trip Comparison

Book Now - Rates & Dates
Rafting Gift Cards

Bird and fish

Yosemite Rafting Blog

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SIERRA MAC RIVER TRIPS

Rafting the Rivers of Yosemite
Marty & Tom McDonnell – Outfitter
Cell and Text Phone – 209.591.8027
International Calls – 001.209.591.8027
Email – contactus@sierramac.com
P.O. Box 264 – Groveland, CA 95321
27890 CA HWY 120, Colfax Spring
13.5mi East of Groveland, CA

National Parks ServiceUS Forest ServiceCA State ParksBLMTuolumne River TrustFriends of the RiverSierra Nevada Geotourism
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