Gardner River

The Gardner River starts as snowmelt running down from Joseph Peak in Yellowstone’s Northwest Corner. After making its way to Gardner’s Hole, a subalpine basin behind Swan Lake flats, it combines with the Fawn, Panther, Indian, and Obsidian creeks around the Indian Creek campground.

Near the Grand Loop Road, this area is frequented by families (kids under 11 can fish with worms here) and anglers looking to take advantage of the small brook trout that aren’t too picky about what they eat and can be especially fun to catch during hopper and terrestrial
season.

As the river crosses the Norris-Mammoth road it passes into an area called Sheepeater’s Cliffs, cool columnar basalt lava flows named after the Tukudika, or Sheep Eaters—a band of Eastern Shoshone Indians who lived in the park. Here it is fishable for a short stretch but soon the canyon walls close in on the river making it nearly impossible to access, which isn’t a big deal since it is nearly devoid of any relevant fish population.

In the canyon, the river drops over Osprey Falls, which is a popular hiking destination accessible from the Bunsen’s Peak trailhead. Below the falls, the river continues through Sheepeater Canyon, where it picks up water from Glen Creek. As the terrain flattens out, small rainbow, brown, and cutthroat trout, plus mountain whitefish, sometimes join the brook trout in the river, which is more of a mountain stream at this point.

But, by the time the river flows under 175-foott-high bridge on the Mammoth-Tower Junction road and Lava Creek flows into the Gardner, the brook trout start to disappear and the river becomes a much wider and formidable presence on the landscape.

The remaining 15 miles from the bridge until the Gardner flows into the Yellowstone River in the town Gardner, Montana is the most popular section for fly fishermen. Flowing through the Gardner Canyon, this section is a mix of boulder-filled pocket water, wandering meadows, riffle runs, and braided channels, all of which can hold trout that are typically in the 8-12 inch range, but can surprise you with a 16+ inch fish now and again.

Though it is a walk-and-wade-only river, the old Gardiner-Mammoth road ran right along the Gardner, making it a very accessible river for fishermen for many years. But the flood of 2020 destroyed much of the road and it was rebuilt further from the river, making the main access points by the Mammoth-Tower bridge, behind the employee housing area in Mammoth Hot Springs, and near park’s entrance in Gardiner. From these entry points, anglers need to hike up and down the river and be prepared for rocky and sometimes steep terrain.

Though not known for its sustained hatches, in late June/early July you’ll find Salmonflies, joined or followed close by Golden Stones. August evenings can also see the emergence of Caddis while spring and fall BWO sightings are also common.

The landscape around the Gardner is considered a high-altitude desert and this rocky and dry landscape can make for great terrestrial fishing during the summer months. Overall, due to the nutrients supplied by many tributaries and thermal heated waters, the Gardner has a rich aquatic food chain and thereby fishes well all year long.

Since 2024, from Osprey Falls to the confluence with the Yellowstone, the Gardner is open to fishing all year round, one of only two such waters in the park. This is especially exciting because in the fall and winter, the river is home to brown trout that migrate from the Yellowstone River into the Gardner to spawn. This can afford anglers the opportunity to land large fish in the 20-inch range in a relatively small body of water.