The Gardner is a smaller river located in the north-western corner of Yellowstone National Park. It is a tributary of the Yellowstone River, and the two meet right at the Park boundary at the town of Gardiner, MT. The Gardner fishes well throughout most of the Yellowstone Park season and is one of the more consistent fisheries in the Park.
Headwaters to Osprey Falls
The Gardner begins as a small meadow stream flowing out of the Gallatin Mountains. The stream crosses under the road beside the Indian Creek Campground and this is a popular area to fish. Brook Trout live here, and most are small, under 12”. They tend to be eager to rise to a dry fly, however, and provide some good action. Fishing is best here during July and August.
Below the campground, the river digs into an increasingly rugged canyon and eventually plunges over Osprey Falls. This section of the river is tough to access and fish, but the falls are an important feature because they separate the fish populations below.
Osprey Falls to Boiling River
Below Osprey Falls, the river is dominated by Rainbow Trout, with a good population of Browns and Cutthroats as well. The fish are a bit larger here, some stretching up to 15” and occasionally bigger. Access is relatively difficult to this reach because it flows through a canyon. The road crosses the river just east of Mammoth and it is possible to hike in here, as well as a few other locations.
The fishing season here usually begins in late June as the runoff begins to subside. Nymphing will be best in the early season, with larger stonefly patterns being a good choice. Dry fly fishing begins with the Salmonfly hatch in early July, followed closely by the Golden Stones. The river sees an excellent Caddis hatch during the evenings in late July and August. Terrestrial fishing is a good in August and early September, as the dry, grass and sagebrush covered surroundings are prefect grasshopper habitat. During fall, nymphing becomes important again, especially in the morning and on cold days. Hoppers will still work on warm, sunny days and Blue Winged Olives will hatch on cloudy afternoons.
Boiling River to Mouth
The Boiling River pumps a large volume of 130 degree water into the Gardner, changing its character significantly. Increased nutrients lead to more bugs and larger fish. The warmer temperatures make for better fishing during the early and late season, but can hamper fishing during the dog days of summer. Access to this stretch is very easy, as it is mostly within sight of the road.
This stretch will fish intermittently throughout the runoff period from Memorial Day weekend until late June. The river will be muddy during periods of warm weather but will clear quickly when it cools off. Nymph fishing works well, with large stonefly nymphs being the go-to. This section sees an excellent Salmonfly hatch at the end of June and beginning of July. A tremendous Caddis hatch can also be encountered during the evenings from mid July through August. It is important to pay attention to water temperatures during August, as the river can be too warm for fishing on hot afternoons. If temps are cool enough, hopper imitations are the top choice. Fall fishing follows the same pattern for the above section, although the section below the Boiling River will fish all the way until the Park closes in November due to the warm water influence.
Contact Montana Angler Fly Fishing for guided fly fishing trips in Yellowstone National Park