O'Neill Regional Park spans 4,000 acres across Trabuco and Live Oak Canyons in Orange County, with over 23 miles of trails winding through coast live oak and sycamore groves. The heavily wooded sections provide genuine shade on warm days, which matters when you’re out here with your dog for hours at a time. You’ll see wild buckwheat, sagebrush, and chaparral as you walk — the landscape changes noticeably as elevation shifts through the canyons.

Dogs are allowed on all paved trails as long as they’re leashed to six feet or less, so you have plenty of options whether you’re doing a short morning walk or a longer afternoon hike. The trails accommodate hikers, bikers, and people on horseback, so expect to see a mix of users, particularly on weekends. Bring more water than you think you’ll need — even the shaded sections get hot, especially from late spring through early fall, and your dog will drink more than usual on trail days.

If you want to stay overnight, the campground allows dogs, which opens up the possibility of a real camping trip rather than just a day visit. Picnic areas with barbecue and tables are scattered throughout the park, available first-come, first-served or by reservation. The picnic spots are genuinely useful for a midday break or for families who want to settle in one place rather than do a long hike.

The park gets busier on weekends and holidays, so weekday mornings tend to be quieter if you prefer fewer people on the trail. Parking fills up during peak times, particularly near the main trailheads. The terrain varies enough that you can choose easier, flatter sections or tackle steeper canyon routes depending on what your dog handles well and what you’re in the mood for that day. There’s real substance to this park — it’s not a quick urban green space but an actual backcountry experience within Orange County.