Preparing for Your Visit

The sun can burn your skin, damage your eyes, and make you dehydrated. Protect your skin from the sun with clothing (hats, pants, etc.) and sunscreen, and protect your eyes with UV-protective sunglasses. 

Carry water, and drink regularly, before you feel dehydrated.

If you get hot, dizzy, nauseated, or have cramps, take breaks in the shade and communicate with your docent.

Symptoms and first aid measures for heat-related illness

If you know that you are allergic, carry your EpiPen. 

If you are allergic and are stung, seek immediate medical attention. If you use your EpiPen, go to the hospital immediately.

If you have never been stung before and develop a concerning reaction after being stung, go to the Emergency department or, if needed, call 911.

Reactions to be concerned about include the following:

• A rash that spreads to large areas of the body
• Rapidly spreading swelling
• Any swelling of the tongue or throat
• Difficulty speaking or swallowing
• Wheezing
• Fainting
• Chest Pain

For most people, most stings require only first aid care:

1. Remove the stinger immediately
2. Apply ice or a cold pack
3. Take an antihistamine if itching is present
4. Wash the area with soap and water
5. Apply topical hydrocortisone cream if the area is locally swollen and/or itchy
6. Watch for infection over the next few days and seek medical attention if you have concerns.

Snakes are common in the area and are most often seen on trails in the morning and early evening. The Northern Pacific rattlesnake, also called Western rattlesnake (Crotalus oreganus oreganus) is native to San Mateo County. Rattlesnakes can be identified by the distinctive tail and triangular head which is broader than the body. 

If you see a snake, back away to a safe distance (at least 12 feet), and notify others nearby to avoid it. Do not attempt to capture, poke, or move the snake.

If bitten, call 911 immediately and seek medical attention

Poison Oak is prevalent at Jasper Ridge and most of the natural areas in the San Francisco Bay area. It can grow as a shrub or as a vine and is recognizable by a grouping of three leaves which range in color from green, to yellow, to red. When Poison Oak is contacted, its oil may cause an irritating rash.

If you come into contact with poison oak:

• Wash your skin with soap and warm water as soon as possible (The oil typically penetrates the skin within ten minutes). Scrub under fingernails with a brush to avoid spreading oil to other parts of the body.
• Reactions range from very mild to very severe, sometimes requiring emergency care at the hospital.
• If rash develops, calamine lotion may be used on the skin to decrease itching. This, as well as other ointments and creams, can be found at your local drug store. Rashes usually last for a week or two.
• Call your physician if the rash/itching is severe or does not stop.

Additional information:

Poison ivy, oak, and sumac: overview, symptoms, causes, treatment

Good footwear helps maintain footing and protects your feet against rocks, sticks, and other hazards. Watching your step is also important to prevent tripping. 

Choose a hiking boot or shoe to provide traction on trails with mud, debris and steep slopes. 

Though rarely seen by people, mountain lions may be active at any time of day at Jasper Ridge.  

Never approach a mountain lion.

• If you spot a mountain lion, move away from it, but do not run or turn your back.
• Most mountain lions will try to avoid confrontation. Always give them a way to escape.
• Aim to appear bigger by standing upright, raising your arms, waving your walking stick, opening your jacket, etc.
• If the lion behaves aggressively, wave your arms slowly and speak in a loud voice, and throw objects.
• If attacked, fight back! Try to remain standing to protect your head and neck.
• Report sightings immediately.

Additional information on mountain lions:

• Biology and behavior of mountain lions
• A mountain lion workshop and report by the Rising Environmental Leaders Network on mountain lions at Jasper Ridge

Wild turkeys are in introduced species in the Bay Area and are prevalent at Jasper Ridge

If approached by a wild turkey:

• Do not run away. Use whatever you’re carrying to block its approach toward you, e.g, a backpack, bag, or walking stick.
• Report the encounter to a Jasper Ridge staff member.

West Nile virus is present in San Mateo County. The main vectors are Culex mosquitoes. 

You can help protect yourself by wearing insect repellent to prevent mosquito bites, especially in the early morning and near dusk, when mosquitoes are most active

Visit the California Department of Public Health's comprehensive website on West Nile Virus, which includes weekly updates on case numbers. 

Trombiculid mites, also known as harvest mites or chiggers, live in tall grass and brushy environments common at Jasper Ridge. The larval stage of these mites can bite humans, causing itching and skin irritation that may last for up to two weeks.

Applying insect repellent can help deter chiggers. As an added precaution, change clothes after hiking to prevent larvae from moving from clothing to skin. Chiggers are most active during the dry season, from late spring through early fall.