Snakes on a trail and other hiking dangers to avoid near San Francisco

Brian Wong was riding along the Luiz Fire Road in April when something moved in the dirt ahead of him: A rattlesnake. 

Wong hopped off his bike in time to take a video of the big baby before it slithered into the bushes in the hills of northern San Rafael. But just a few weeks later, on a nearby track, the veteran Marin mountain biker found his ride again halted by a rattler crossing the trail.

“Yeah, when it gets hot, they all come out,” Wong said of the snakes. “It’s pretty neat to see nature up close.” 

But other residents are more rattled by the seemingly large number of snakes being seen around the Bay Area this spring. 

While climate change’s warmer weather is driving the growth in the local rattler population, most of the snakes encountered in the region are likely harmless garter snakes. Garters are more slender with a narrow, round head compared with the diamond-shaped head and thicker body of a rattlesnake. 

But since you’re not likely to have time to closely examine the face of a snake you meet on a trail, experts have one crucial piece of advice.

“Leave snakes alone,” said Vince Anibale, chief ranger of the Bay Area District of California State Parks. “Rattlesnakes are definitely a threat, but if you leave them alone, they leave you alone—especially in the Bay Area.”

Rattlesnakes rattle when they feel threatened, warning hikers of their presence. And though the rattle of a baby snake may be undeveloped and harder to hear, experts say a juvenile’s bite is no worse than that of its parent. If a human simply gives the snake space and doesn't poke at it, both creatures can go on with their days.

“Rattlesnakes in the Bay Area are fast so if you avoid them, they will move along,” Anibale said. The bite victims he has seen in his 20-plus years as a ranger are curious dogs going in for a sniff and humans showing off by picking up a snake. In fact, studies of snake bites have found that the portion of victims who get bitten without handling or harassing the snake is very small.

If you manage to beat the odds and get bit by a rattlesnake in the Bay Area, Anibale advises calling 911 immediately and getting to a doctor as fast as possible. “The faster the better—within four hours, for sure,” said Anibale.

Though the state doesn’t keep official statistics about hazards in its parks, local sites advise visitors to be aware of four concerns: rattlesnakes, poison oak, mountain lions and ticks. Here is Anibale’s advice for dealing with other potential pitfalls on the trails.

“In all honesty, poison oak is the biggest danger to people in the parks,” said Anibale, who hears about more problems from encounters with the rash-causing plant than any other issue. “It’s important to remember that poison oak leaves come in all different colors—red, yellow and green.”

Rashes are especially common in early spring when the plant moves from winter’s bare stick to summer’s green leaves, which is why staying on trails and out of bushes is the best way to keep from getting poison oak. “We [rangers] try to wear long sleeves and long pants to avoid getting it,” said Anibale. 

If you suspect you might have come in contact with the nasty plant, he advises washing right away with cold water, soap and a washcloth or something to wipe off the oil versus running water alone. 

“Ticks are prevalent throughout the Bay Area,” said Anibale, who recommends having your buddy check your back and neck after any time on the trail. 

If one bites you, it’s important to get it off as soon as possible to prevent transmission of Lyme disease that can be carried by ticks.

“I tell folks to take the tweezers and grab as close to your skin as you can until the tick releases,” said Anibale. “Don’t cover it in Vaseline or put a match near it—just get it off as soon as possible.” He said to treat the site with rubbing alcohol and call your doctor if a rash appears. You can also save the tick in a jar if you are concerned about disease.

“I’ve been working out here for 20 years, and we’ve had very few mountain lion interactions, no problems in the state parks,” Anibale said. “We know they’re around because we see them on wildlife cameras, but they’re smart and stay to themselves.”

If you encounter a mountain lion on Bay Area trails, Anibale said to extend it the same courtesy you would a rattler: give it space. 

“Mountain lions are very elusive, and they try to stay away from people,” said Anibale. But if one comes toward you, he says to “act big” and yell until it leaves the area—at which point, you should scoot along, too.

Anibale said a genuine concern for Bay Area hikers is exposure. While this winter, some park visitors were surprised and unprepared for snow and freezing temps found on trails, a more common situation is excessive heat.

Rising temperatures caused by climate change have increased the number of heat-exhaustion rescues needed at parks around the state. Obviously, the best way to prevent a problem is to bring plenty of water and avoid hiking during the heat of the day, especially in summer. 

But after all his time in Bay Area parks, Anibale said the scariest situations he’s encountered involve none of the dangers discussed above. 

“It’s probably the people,” Anibale said. “As a peace officer, you run into a lot of different people in the parks. Sometimes they need help, and sometimes they don’t want help.”