DUI Checkpoints in Mariposa County, CA
Mariposa County, tucked in the scenic Sierra Nevada foothills, is the gateway to Yosemite National Park and home to small but busy communities like Mariposa, Coulterville, Catheys Valley, and El Portal. While it’s a quiet, rural area, the county sees a steady flow of tourists, especially during spring and summer, thanks to its proximity to national parks, campgrounds, and mountain getaways.
In 2024, Mariposa County saw over 30 DUI-related incidents, including 2 fatal crashes and several injuries. To keep both locals and visitors safe, law enforcement actively sets up DUI checkpoints during major holidays, festival weekends, and Yosemite’s peak tourist seasons.
Most checkpoints happen between 6 PM and 11 PM, and officers look for signs of impairment, check licenses, and conduct field sobriety tests when necessary. Their goal is to catch and stop impaired drivers before tragedy strikes.
Here are the top DUI checkpoint locations in Mariposa County with up-to-date info:
Mariposa – Highway 140 near 8th Street
Exact Location: Just outside downtown Mariposa, near local shops, restaurants, and hotels.
Agency: Mariposa County Sheriff’s Office
Details: This is the most active DUI checkpoint area in the county. It’s often used during the Mariposa Butterfly Festival or busy tourist weekends. The location is well-lit and close to hotels and bars, making it ideal for monitoring evening traffic. Officers usually run checkpoints Friday and Saturday nights from 6 PM to 11 PM, focusing on impaired driving, valid insurance, and registration issues.
El Portal – Highway 140 near Yosemite View Lodge
Exact Location: Right before the entrance to Yosemite National Park.
Agency: California Highway Patrol – Mariposa Area
Details: This is a major tourist checkpoint, especially during holiday weekends, summer months, and national park events. CHP officers here monitor for drivers coming out of Yosemite after a day of hiking, camping, or drinking at local lodges. The setup includes cones, flashlights, and support units. Officers check for alcohol, cannabis use, and signs of fatigue.
Coulterville – Greeley Hill Road near J132 Junction
Exact Location: Near the junction of local roads that connect to small mountain communities.
Agency: Mariposa County Sheriff’s Office
Details: This rural checkpoint is active during local fairs, small-town celebrations, and weekends when campgrounds fill up. Officers often stop every 3rd or 4th car and conduct brief checks. The area lacks street lighting, so officers use high-beam floodlights and reflective signs for safety. Checkpoints usually operate from 5:30 PM to 10 PM.
Catheys Valley – Highway 140 near Hornitos Road
Exact Location: Just west of the main town area, along a major rural route connecting Merced and Mariposa.
Agency: California Highway Patrol
Details: This location is used during holiday weekends and busy Yosemite travel days. Since it’s a connector highway, the CHP focuses on speeders, long-distance drivers, and signs of intoxication. Officers may also perform random license and registration checks, and this checkpoint often includes drug recognition experts (DREs).
Bootjack – Triangle Road near Darrah Road
Exact Location: A key intersection between Mariposa and the Sierra National Forest access routes.
Agency: Mariposa County Sheriff’s Office
Details: This checkpoint targets traffic heading into the hills for camping, off-roading, and hunting trips. Officers usually stop vehicles on Friday evenings and Sunday afternoons, when weekenders are either arriving or heading home. The checkpoint runs from 4 PM to 9:30 PM, with a focus on impaired driving, off-road vehicle compliance, and open container laws.
Even though Mariposa County is rural and peaceful, DUI checkpoints play a big role in keeping the roads safe for everyone—locals, tourists, and families visiting Yosemite. Law enforcement isn’t just looking to write tickets—they’re trying to stop drunk and drugged drivers before they cause harm.
If you’re planning to drink, use cannabis, or party in the mountains, don’t drive. Use a designated driver, get a ride, or book a place to stay. It’s not just smart—it could save a life, including your own.