Lagoon Valley Park’s 7.5-mile loop trail near Vacaville is one of those satisfying moderate hikes where you actually feel like you’ve done something by the end. The trail winds through Pena Adobe and Lagoon Valley Park, mixing open grassland with views across the water and the rolling terrain around it. Your dog needs to stay leashed the whole way, which is fine—the path is well-established and easy enough to navigate without worrying about them wandering off.

The trail draws a mix of hikers and mountain bikers, so you might see people on both two legs and two wheels. Expect company on weekends, especially in cooler months. What makes this loop solid is the variety: you’re not staring at the same landscape for the entire hike. The lake views come and go, and the open hillsides give way to sections with more vegetation.

There are a few things to know before heading out. Cattle graze in parts of the park, so keep an eye on your dog and stay on the marked trail—cows generally don’t bother hikers, but they’re just another reason to keep your dog close. During wet months (typically November through March), the trail gets genuinely muddy in spots. If you’re going after heavy rain, be prepared for slick sections and bring something to clean paws before getting back in the car.

You have three access points: Butcher Road and Pena Adobe Regional Park both have free parking, while Lagoon Valley Park itself charges a fee. Butcher Road tends to be quieter if you’re looking for a less crowded experience. Get there early on nice weekend days, though—this loop is popular enough that the parking fills up by mid-morning during the season.