Rattlesnake, Mt. Diablo

East Bay Regional Park District (EBRPD) would like to remind residents and hikers that spring and summer are active snake seasons in parks and open spaces.  

As the weather heats up, park district staff notes rattlesnakes in particular become more active. Like humans, they like to explore when the weather gets warm, and snakes are able to regulate their body temperature by moving in and out of shade. A warmer body allows a snake to move faster when trying to catch prey. Depending upon the breed, a snake can eat insects, slugs, frogs, birds, bird eggs, small mammals and other reptiles.

Several kinds of snakes live in the Bay Area. Most snakes are harmless to humans and pets, but any snake will bite in self-defense. As a rattlesnake bite is poisonous, it is considered a medical emergency, and anyone inflicted should call 9-1-1.

In any given week, the park district staff receives multiple reports of rattlesnake sightings and sometimes attacks, including the recent incident with a 47-year-old male, who was bitten by a rattlesnake near the top of Mission Peak Regional Preserve in Fremont. The victim was taken by helicopter to the hospital. Another case saw a pet dog inflicted at Del Valle Regional Park in Livermore, on the Arroyo side along the trail. Additional rattlesnake sightings were reported at Castlerock Regional Recreation Area in Walnut Creek in a picnic area, on the Delta DeAnza Regional Trail in Pittsburg, as well as in the parking lot outside of EBRPD Police Headquarters at Lake Chabot Regional Park. No snakebites were reported with those incidents.

Park staff urges taking safety precautions when visiting regional parks, especially at this time of year.

Learning how to identify a rattlesnake is important. Rattlesnakes have a triangular head, which is much wider than the neck; a thick body with dull skin; and black and white bands on the tail, with a blunt rattle at the tip, which may or may not shake in warning. The rattle sounds like bacon sizzling.

If bitten by a rattlesnake, stay calm and send someone to call 9-1-1. The victim should remain calm by lying down with the affected limb lower than the heart. Do not waste precious time on tourniquets, “cutting and sucking” or snakebite kits. If you are by yourself, walk calmly to the nearest source of help, which is another person, a park employee or a phone to call for help. Do not run.

If bitten by any other kind of snake, leave it alone. Wash the wound with soap and water or an antiseptic and seek medical attention.

If you are not sure what kind of snake bit you, check the bite for two puncture marks (in rare cases one puncture mark) associated with intense, burning pain. This is typical of a rattlesnake bite. Other snakebites may leave multiple teeth marks, without associated burning pain.

Snakes are an important resource in the natural environment. They are prime controlling agents of rodent, insect and other reptile populations. They must be enjoyed from afar and left where they are found. It is illegal to collect, kill or remove any plants or animals from the East Bay Regional Park District. 

The following are safety tips to follow when visiting natural parks:

  • Always hike with a friend, so you can help each other in case of emergency.
  • Look at the ground ahead of you when walking.
  • Look carefully around and under logs and rocks before sitting down.
  • Avoid placing your hands or feet where you can’t see clearly.
  • Check the immediate area around picnic tables, campsites and barbecues before using them or camp area. If you encounter a rattlesnake in these areas, notify park staff. Do not disturb it, stay calm, give it plenty of room and leave it alone.

For more information on common snakes in East County, visit