Grizzly Island Wildlife Area encompasses a stunning 8,600 acres within the expansive 84,000-acre Suisun Marsh, the largest contiguous estuarine marsh in the United States. This unique habitat supports over 200 species of birds, and it’s a genuinely wild place to explore with your dog—the kind of landscape where you might actually see what you came for, whether that’s a great blue heron or a pair of rails moving through the marsh grasses.

The preserve is generally open for hiking from February to July, then again at the end of December, with late winter and spring offering particularly breathtaking views and wildlife activity. You’ll want to know upfront that not all trails are marked, so bringing a map is essential for navigating the unmarked paths. The nine staging areas give you multiple entry points depending on where you want to start your day.

Checking in with the rangers when you arrive is worth doing—they can tell you about pet policies and point you toward the best areas to explore with your dog. If you prefer a less strenuous outing, the self-guided driving tour along Grizzly Island Road covers approximately 7.5 miles of unpaved road running through the heart of the wildlife area. It’s a solid option if your dog does better with a relaxed pace, and you’ll still get decent chances to observe wildlife from the vehicle.

Before you head out, pack drinking water for both of you, binoculars for bird watching, a field guide if you want to identify what you’re seeing, and appropriate footwear for wet or muddy ground. Sunblock and insect repellent will make your visit more comfortable—this is marsh country, and the bugs can be present depending on the season. Sticking to the signage and area regulations protects the wildlife and keeps the experience good for everyone visiting. The threatened and endangered species that live here are part of what makes this place worth the drive from the Bay Area.