Guide to Fly Fishing the Gardner River

Fishing the Gardner River


The Gardner is the closest river to the town which took its name (the river's name is spelled right, well-meaning cartographers added the "i" in the name of the town). It is fishable over its entire length, from the headwater meadows stuffed with brook trout to the endless pocket water in the canyon between Osprey Falls and Gardiner, where it meets the Yellowstone. It runs along the road for much of its distance, but due to its character (steep and rugged) it is seldom crowded except during the Salmonfly hatch and occasionally in the fall, when the browns are running. The Gardner has something for everyone, from brookies and rainbows at high summer to huge browns in late autumn.

Like the Yellowstone between the Falls and Livingston as well as the Lamar drainage, we consider the Gardner our home water. For the best information on fishing this river, rely on us. Many of our custom fly patterns were created and are tied by Matt Minch of Gardiner, who has fished the Gardner more than anyone in history and holds the river record, a brown over nine pounds. Though his fly patterns work well elsewhere, most were designed specifically for the Gardner. Our shop is the only place you can get them. If you'd like targeting the fall runner browns up from the Yellowstone, our guides are your best resource, since we fish the river religiously in the fall and spend a lot more time pursuing its runner browns than any other guides.

Description and Access

The Gardner is best divided into three sections. The first section, the upper river, holds brook trout and some rainbows in its lower end. This is beginner water. The top portion of the upper river consists of meadows reminiscent of Slough Creek or Soda Butte, but stuffed with brook trout instead of cutts. Originally fishless, fisheries managers made a grave error by stocking Eastern brook trout instead of Slough Creek cutts early in the 20th century, but such is life. Below the first point where it crosses the road, near the Sheepeater Picnic Area, the first portion of the upper section ends, and the Gardner dives into a canyon and begins to pick up speed. For the next two miles, the river consists of long stretches of pocket water separated by long pools, plus several small waterfalls which dig the river deeper into its canyon. The upper river ends at Osprey Falls, which serves as a barrier to fish populations and, to a large degree, to insect types. The second section of the river begins here. The riffles all but end, save for two brief stretches, and though there remain a few small pools, the stream largely flows through pocket water in a canyon filled with boulders ranging in size from basketballs to pickup trucks. Rainbows predominate from here on, but brook trout, cutthroats, and browns, plus whitefish, are also possible. The third section begins at Boiling River, a large hot spring that warms the water considerably. Below this point the water character resembles that of the second section, but the water is much warmer. This extends the fishing season in spring and fall, but means that some days in midsummer (or weeks during low water years) find the lower river too warm to fish.

Access is varied. The headwaters are accessible by hiking a fairly short distance over several trails or by bushwhacking down into the top of Sheepeater Canyon. The second section can be accessed by hiking to Osprey Falls, dropping off the so-called "High Bridge" between Mammoth and Tower, or on the Lava Creek Trail. The third section of the river is right beside the Mammoth-Gardiner road for most of its distance, while the top can easily be reached by taking the Boiling River Trail and the bottom can be reached by taking the unnamed trail to the river's mouth, which heads in Gardiner itself and is where whitewater companies put in their rafts to float the Yellowstone. The Park boundary runs right through the Gardner's mouth, meaning the river is entirely within the Park.


Fish Species Abundance
Brook Abundant above Osprey Falls, shading from common to rare below.
Rainbow Absent to rare above Sheepeater Cascade. More are added below each cascade until they actually outnumber brook trout even before you reach Osprey Falls. Abundant below Osprey.
Brown Common Osprey Falls to Boiling River, Abundant below Boiling River. Many more enter in the fall.
Cutthroat-Rainbow Hybrid Common below Osprey Falls.
Cutthroat Actually fairly uncommon, and only below Osprey Falls. Most common in early summer, when some run up from the Yellowstone. Otherwise, most common around Lava Creek.
Whitefish Uncommon to common below Osprey Falls. Not as abundant as in the Yellowstone, which might explain their comparatively large average size.
Sucker Mentioned for completeness. There's a big spawning run in June, and a few monsters remain through the season. A 24" sucker can put up quite a tussle, but it's disappointing when you see the orange colors and think it's a lunker brown.

The upper Gardner and the river below Osprey Falls fish quite differently, and provide different things for the angler. The upper river is populated by small brook and rainbow trout that aren't at all choosy about what they eat, making it an ideal choice for a place to take children or other beginners. An ultralight rod and dry flies like the Trude are all you need here, though you may add a small beadhead Prince if you wish. The meadows upstream of the road, in Gardner's Hole, are also extraordinarily lovely and remote, which make the short hike a good one for anyone who likes to fish in solitude in a beautiful place. Once in a blue moon someone will get a fourteen-inch brookie in this area, but more commonly the best fish of the day will be a ten-incher, with most of the rest between six and eight inches. The season gets started here in late June or early July, after runoff recedes, and ends in early September, when almost all the brook trout head far up tiny tributaries to spawn.

Below Osprey Falls, the average fish size remains fairly small, at probably eight to twelve inches, with the larger fish below Boiling River, but there are always some larger rainbows, cutts, and whitefish present. Many of the latter exceed two pounds and can really cause some excitement in fast water. Through most of the season, you can expect some catches of sixteen to eighteen inches, with 14-15 inches about average for the day's best fish. The pocket water here calls for short, precise casts and good short-distance line control, but otherwise this is good water for novices who are capable of casting 15-20 feet accurately.

Early in the season stonefly and attractor nymphs are the best and really only bets, as the river is still very, very high even after it clears sufficiently. More importantly, the Gardner below Osprey Falls sees the best Salmonfly and Golden Stone emergence of any river in the Park except arguably the Yellowstone, so the fish are really keying on the nymphs of these insects as they move towards the bank to emerge. Adult Salmonflies can be present below Boiling River starting around June 20, though they more commonly begin emerging in earnest around the 27th. They will remain available in earnest below Boiling River until about July 10-15, though strays from above Boiling River may still bring rises even later. Above Boiling River, strays from downstream may bring rises by June 25, though the best Salmonfly fishing is from July 10 or so until the 25th. In wet years with cool summers, we have seen fish eating adult Salmonflies above Boiling River as late as August 6, probably the latest of any stream in the Rockies. An important tactic on the Gardner is to fish a fur and feather Salmonfly like the Parks' Salmonfly slightly wet, since the roughness of the water's surface means Salmonflies which hit the water, either on accident or to lay eggs, are never getting up again. Instead they get sucked under from half an inch to six inches, making them easy prey.

The caddis, small stonefly, and attractor dry bite begins a few days after the fish begin rising to Salmonflies. Late in July, the stoneflies begin to be replaced by terrestrial insects, and by mid-August terrestrials are the top dry fly bet. #12-16 attractor nymphs should always be fished as droppers, unless you're fishing a pair of dries. The only summer hatches that bring up large numbers of selectively rising fish are evening caddis hatches, but the trout will often take an attractor like a Trude as often as they'll take an X-Caddis or Elk Hair. The Gardner fishes well between Osprey Falls and Boiling River from the time it clears until late October, but note that the section below Boiling River can be too warm on hot August afternoons, especially in low water years and during heat waves.

Late in the season, brown and some rainbow trout move into the Gardner from the Yellowstone. Most of these runners range from fourteen to twenty inches, but they get much larger. The river record is close to thirty inches, and 24-inch fish are caught every year. These are powerful fish, and even when hooked in a pool they offer a nip and tuck fight, requiring a six- or seven-weight rod and 2-3X tippets. In fast water you will lose as many as you land, because if a fish gets downstream of you, it's gone. Important flies for these runners run from moderate-sized and nondescript nymphs like the Bead, Hare, and Copper up through standard stonefly nymphs. As spawning season approaches in late October, larger and stranger irritators like Matt's Creep, a flashy rubberleg nymph, and streamers begin to work as well as the smaller irritators. Egg flies become critical around October 15, and can bring some fat rainbows that have followed the browns up from the Yellowstone. From October 15 onward, beware of redds. If you see a dish-shaped light-colored depression on the bottom, stay away from it. Do not fish over it and certainly don't walk near it. The Gardner does not have a great deal of spawning water, so it's even more important to let actively spawning fish do their business in peace. There are plenty of resident fish and pre-spawn browns in the deeper pools that won't be unduly bothered by anglers. Holding water for runner browns changes from year to year, so your best option on getting a handle on where to look for these sizable trout is to hire a guide from our shop for at least a half day.

One other opportunity is present at the same time the fall-run browns are running. The Gardner can see excellent hatches of fall BWO (Gray Baetis) starting in early September and running through the end of the season below Boiling River. While not many runner browns will rise to these insects, a few will, and at times the number of resident fish eating these insects can be staggering. While we usually focus on runner-hunting, it's hard to ignore a pool that appears to be boiling with rising trout, even if most of them are under 14" in length.

Quality of Fishing By Period: X=high, x=moderate, x?= variable, blank=poor or closed
  May 6/1 6/15 7/1 7/15 8/1 8/15 9/1 9/15 10/1 10/15 Nov.
Above Osprey Falls       x? X X X x?        
Osprey Falls to Boiling River     x? X X X X X X X x? x?
Boiling River to Mouth x? x? x? X X x? x? X X X X X

Gardner River Hatch Charts and Fly Pattern Recommendations
  Timeframe: X=major importance, x=minor importance, blank=unimportant
Insects May 6/1 6/15 7/1 7/15 8/1 8/15 9/1 9/15 10/1 10/15 Nov.
Fall BWO (Gray Baetis)             x x X X X X
Tan Caddis (Hydropsyche)       X X x            
Caddis, Other       x x x x x x      
Yellow Sally Stone     x X X x            
Salmonfly     X X X              
Golden Stonefly     X X X x x          
Terrestrials         X X X X x x    
Other Trout Foods May 6/1 6/15 7/1 7/15 8/1 8/15 9/1 9/15 10/1 10/15 Nov.
Attractor Dries     x X X X X x x x    
Attractor Nymphs X X X x x x X X X X X X
Stonefly Nymphs X X X X x x X X X X X X
Streamers and "Aggravators" x x x           x X X X
Egg Flies x x x           x x X X

Gardner River Top Flies
Minch's Stone, Black, #4-6
Minch's Stone, Golden, #8-10
Matt's Bead, Hare, and Copper, #10-16
Turck's Tarantula, #10-12
Coachman Trude, #12-16
Yellow Stimulator, #8-16
Purple Haze Cripple, #16-18
Parks' Salmonfly, #4-8
Brown Girdle Bug, #4-6
Tunghead 20-Incher, #8-12

phone 406 848 7314, address 202 Second Street South PO Box 196 Gardiner, MT 59030 E-mail Walter Wiese E-mail Richard Parks link to PFS Youtube Channel link to PFS Facebook

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