Coexisting with our rattlesnakes

Boulder County is home to the prairie rattlesnake (Crotalus viridis), the only venomous snake species in the area. These snakes are most active from April through October, especially during warm daylight hours and at dusk. They prefer open grassy areas and rocky outcrops.

Though often feared, rattlesnakes play a crucial ecological role. As top predators of small mammals like mice and rats, they help control rodent populations that can carry disease and damage crops or native vegetation. In turn, rattlesnakes serve as prey for raptors, coyotes, and other wildlife, supporting the food web.

Rattlesnakes are non-aggressive when left undisturbed and typically give a clear warning rattle before striking. Respectful coexistence—staying on trails, keeping pets leashed, and giving snakes space—is key to avoiding conflicts and preserving this valuable native species.

A prairie rattlesnake at dusk near Middle Fork., lit by car headlights, digesting a mouse,.

Learn more about our beneficial neighbors from Boulder County Animal Protection (aka Animal Control)

Preventing encounters

An option is to apply snake repellants around the home.

• Choose an EPA‑registered product like Dr. T’s Snake‑A‑Way, or a pet‑safe alternative like Liquid Fence.

• Apply in continuous bands around the expected entry zones.

• Reapply every 2–3 months or after rain.

• Always integrate repellents with habitat cleanup, sealing gaps, and exclusion fencing for best results.

Encountering a snake

Outside

If you see a snake in your yard, stay calm, back away slowly, and give it space—most will leave on their own. Keep pets and kids away. Animal Protection says you can also use a hose to spray with water to encourage them to leave.

Inside home or garage

If a snake is inside the home or garage, Animal Protection (Animal Control), will come to you and relocate outside.

• Call Boulder Co Sheriff non-emergency line:  303-441-4444

• Press 3  for county resident option

• Leave a message for animal control, they will call back soon to assist

Thank you for helping protect rattlesnakes in our community and supporting a healthy, balanced ecosystem where people 🏠 and wildlife 🐍 can safely coexist!