Horseshoe Lake sits at the end of Lake Mary Road in Mammoth Lakes, where the scenery shifts from alpine forest to open water ringed by granite peaks. The lake itself is shallow and clear enough that you can see straight to the bottom in most spots—great for dogs who like to wade without suddenly dropping off into deep water. Your dog can swim here, and the rocky shoreline gives plenty of places to shake off afterward without tearing up a grassy bank.

The Horseshoe Lake Loop Trail circles the water in about three miles, and it’s an easy enough walk that most dogs handle it without complaint. The trail stays mostly level and close to the lake, so you get that water view the whole way around. On the way out, you’ll pass through lodgepole pine forest that offers some shade, which matters when you’re at this elevation and the sun feels closer than it probably is. Leashed dogs are allowed on the trail, and you’ll see a steady stream of other hikers with their dogs, especially on weekends.

The parking area has picnic tables and restrooms, so you can set up for a longer stay if you want to pack lunch. The lake gets busy in summer—the parking lot fills by mid-morning on nice days—but the loop trail itself disperses people pretty well once they head out. If your dog likes to fetch, the rocky beach on the south side of the lake has enough open space to let them run. The water temperature stays cold year-round, which some dogs love and others find shocking, so bring a towel either way.

The elevation here is around 8,900 feet, so if you’re coming from lower elevations, take it easy on the hike. Horseshoe Lake Road can get snowy in winter and spring, so check conditions before driving out if you’re visiting outside summer.