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Sierra Mac River Trips: Pioneers on the Wild and Scenic Tuolumne River

Chamber members since 1979, Sierra Mac’s Marty McDonnell served on the Yosemite | Hwy 120 Chamber board in 1982 when it voted to support Wild and Scenic status for the Tuolumne River, leading the way for Federal legislation to protect the Tuolumne River from the threat of three dams proposed by San Francisco, Modesto, and Turlock.


“This stretch of river now has the reputation of having the best rapids in the country for rafting and kayaking,” said Marty “Mac.” According to Marty, the Tuolumne River, or the “T” as it’s known in the trade, has an especially unique run of rapids through the wilderness that sets it apart from other runs that have extended stretches of flat water. Two side canyons (Clavey and the North Fork of the T) have great natural swimming holes, and are fun for exploring.


In the 1960’s, Marty’s father led family trips that included kayaking and rafting. His older sister, Candy, became one of the first female whitewater kayakers in the world. She passed on this passion to Marty, who started building fiberglass kayaks, renting and selling them to the fine people of the San Francisco Bay Area in the mid 60’s.


Through his sister, Marty became known to Bryce Whitmore, who ran trips on the Stanislaus, the birthplace of commercial rafting in the West. Bryce’s company “Wilderness Water Ways” began exploring the Tuolumne in the late sixties as an option to expand. Marty worked with others to pioneer and sort out the run in 1969 and in 1970, he led the first commercial trip on the Tuolumne.


Marty subsequently took over Wilderness Water Ways and after exploring all over the state, decided to focus on the Stanislaus and Tuolumne Rivers. Following a controversial and political attempt to save the Stanislaus, the Tuolumne became the main focus for what is now Sierra Mac River Trips.

Marty on the "T" 1977.

True pioneers of the sport, no rafts had run the Upper Tuolumne (also known as Cherry Creek) until Marty and three others navigated it in 1973. They had so much fun, they did it the next day as well. Until that point, Cherry Creek was considered unrunnable. But with a craft Marty designed now known as the cataraft, they were able to run the granite gorge of the Cherry Creek/Upper Tuolumne, rated as a Class V rapid. (The International Scale of River Difficulty is the most widely used whitewater grading system. In this system, whitewater–either an individual rapid, or the entire river–is classed in six categories from Class I (the easiest and safest) to Class VI (the most difficult and most dangerous).


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