Bay Area’s largest state park in debate over off-road vehicle use

The largest state park in Northern California, a vast expanse of scenic trails, oak woodlands and breathtaking views of the Diablo Range, is often out of sight and out of mind for many Bay Area residents.

But now, Henry W. Coe State Park, a rugged landscape in the hills east of Morgan Hill and Highway 101, is at the center of a debate about whether California should open more land to off-road vehicles.

Coe park was included in a state law signed by Gov. Gavin Newsom two years ago as a location that the state parks department should consider for expanded off-road vehicle access as part of a wider statewide study to find new locations where people can ride dirt bikes, dune buggies, ATVs and other off-road vehicles.

Environmental groups say the 87,000-acre park, three times the size of San Francisco, would be spoiled if its remote backcountry was opened to Jeeps, motorcycles and other vehicles.

“They would damage the wild areas of the park,” said James Eggers, director of the Loma Prieta chapter of the Sierra Club. “There would be illegal roads created and lots of pollution and noise. There would be more erosion, human waste and habitat damage.”

But off-highway groups say opening the sprawling interior to Coe, a huge collection of former cattle ranches with more than 250 miles of hiking trails and old dirt roads, could provide access to more people, particularly seniors and people with disabilities.

“If it’s possible to open it up for families when the weather conditions are appropriate, it should be open for Californians to enjoy,” said Amy Granat, managing director of the California Off-Road Vehicle Association, a nonprofit group based in Sacramento.

State parks officials plan to hold an “open house” meeting Thursday to discuss the possibilities, which will be part of a wider study called the “Off Highway Vehicle Access Project” to identify potential new sites around California for off-highway vehicle users. The meeting will be held from 4:30 pm to 7:30 pm Thursday at the Pleasanton Marriott, 11950 Dublin Canyon Road in Pleasanton.

Coe park’s trails and former ranch roads are used now by backpackers, horse riders, and mountain bikers, most who access it through the main headquarters on the park’s west side near Morgan Hill.

Map showing Henry W. Coe State Park, southeast of San Jose.The park is considered a hidden gem among Bay Area outdoor enthusiasts, particularly in spring. It is so big that backpackers can wander for a week and not see another person. But because of hot weather in the summer and its remote location, the park receives a relatively small number of visitors — about 50,000 a year.

Last summer, a group of about 40 off-road enthusiasts met state parks officials in the Coe park backcountry to outline their hopes that the area also could be opened to motor vehicles.

The only time vehicles are allowed is once a year, in late April, when state parks officials work with the Pine Ridge Association, a nonprofit group that raises money to help with park projects and activities. During a 3-day weekend, people can drive over the Kaiser-Aetna Road, a dirt road that runs about 12 miles from Highway 152 near Pacheco Pass along the park’s remote east side into the middle of the park near an area called the Orestimba Corrals. Several hundred people buy tickets, and many camp along the dirt road’s edges, hike from vehicles or go fishing in remote lakes in the park.

Granat said she would like to see that road opened regularly to the general public. In years past, it was open on weekends from May to September from Highway 152 to the Dowdy Ranch visitor center, a remote outpost with picnic tables but no electricity or other amenities. That backcountry visitor center was closed during the COVID pandemic and hasn’t been reopened since.

Granat also said that she would like to see some portion of Coe park opened with similar rules to those allowed at California’s nine state vehicular recreation areas. Those parks are run by state parks and used by dirt bikes, ATVs and other off-roaders. They are funded through off-highway vehicle registration fees and gas taxes.

There will be multiple public meetings in the coming months to get input on state parks’ study, said Alexandra Stehl, deputy director for strategic planning of the state parks department.

The agency set up a website this week (at with more information.

Stehl said that her study, which will be finished by the end of 2024, will look at a lot of options, including having state parks pay the U.S. Forest Service or Bureau of Land Management to expand off-highway vehicle access on its federal lands in California, buying private land or expanding existing state off-road parks.

She said that there are no plans to convert any part of Coe park to an off-highway vehicle park. But she noted that state parks officials are considering studying whether to allow street-legal vehicles like cars, SUVs and motorcycles on some of Coe’s backcountry roads as a way for people to more easily access fishing holes, hiking trails and other features.

“The point would be to get to some place, not just speeding around in the park,” she said.

Environmental groups say they prefer the status quo. Eggers noted that all motor vehicles are already prohibited in the 22,000-acre Orestimba Wilderness on the park’s northern edges, which a state-designated wilderness area. Other longtime users agree.

“Expansion could change irrevocably the visitor experience,” said Al Henning, a retired physicist who has hiked the Coe backcountry for 43 years. “You can’t go back once you go down this path.”

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