Gros Ventre River Fly Fishing

Originating in the majestic Gros Ventre Mountain Range, the Gros Ventre River meanders through the untouched landscapes of Jackson Hole’s eastern boundary. This pristine region teems with wildlife. The river, characterized by its swift flow, offers ample pocketwater, runs, and pools, with fewer riffles to explore.

Navigating this section of the river demands dexterity and physical conditioning, especially in the challenging slide area. If you’re uncertain about your wading skills, it’s safer to stick to the accessible streambanks, which still offer ample fishing opportunities. Floating on this stretch isn’t a practical choice.

The Fish

The river holds Snake River Fine-spotted Cutthroat Trout, a small population of remnant rainbows and whitefish. Trout in this region typically range from 8 to 16 inches, with an average size of around 10 inches. Despite their modest size, these fish are abundant and put up spirited battles in the swift-flowing waters. They readily take dry flies, although nymphing is a viable tactic as well. Using 3- and 4-weight rods can provide an enjoyable angling experience.

As for the Gros Ventre River downstream of the Town of Kelly, it doesn’t offer as much prime trout habitat until it approaches the Snake River. However, there are some fish to be found, and accessing them is relatively straightforward along Antelope Flats Road before reaching Kelly. This option is convenient if you have limited time to spare.

Open season on the Gros Ventre is April 1 – October 31. Runoff season typically runs from early to mid-May through late-June/early-July during which time the river is unfishable.

The best time of year to fish this water is from the end of run-off through August – longer if there are sufficient amounts of water.

As with most cutthroat fishing, typically the best time of day to fish is the middle of the day is best, excepting early or late hatches.

Access

From Jackson, drive north on Route 89/191 into Grand Teton National Park. Once in the park, take the first right (about 7 miles from town) onto Antelope Flats Road. Follow this road for about 1 mile past the Town of Kelly and take a right on Gros Ventre Road. Following Gros Ventre Road you will soon exit Grand Teton National Park. Immediately on the right (upon exiting the park) is a small parking area. You can park here, ford the stream, and fish downstream from here for a mile or two. Just upstream of this parking area is the Gros Ventre River Ranch which is private. Do not attempt to ford the Gros Ventre in high water. The bottom is unstable and you may be swept into a deep pool at the base of a small cliff.

Continuing past Gros Ventre River Ranch you will go uphill and soon have some beautiful views looking down on the river below. Once on top of the hill, the second parking area on the right leads to a mild downhill hike to the river. We don’t recommend driving down to the river, if it rains you’ll be stuck. Also do not try to hike straight down the hillside, it is very steep. Use the trail (which is actually a beat up 4-wheel drive road).

If you continue up Gros Ventre Road you’ll soon see the Gros Ventre Slide Geologic Area on your right. Just past this parking lot is Taylor Ranch Road which will take you to the outlet of Lower Slide Lake. Park about 100 yards before the bridge and fish downstream from the outlet.

Lower Slide Lake

he Gros Ventre Slide was created when, in 1923, the side of Sheep Mountain slid into the river, forming Lower Slide Lake. The unstable dam twice gave way soon thereafter, flooding the Town of Kelly until being fortified to its present day condition.

Lower Slide Lake doesn’t get a lot of attention from Jackson Hole fly fishers, not because of a lack of trout, but rather because of the abundance of other angling opportunities. There is a boat ramp and the lake is not so big that small boats are unsafe (though care must be taken at all times when boating anywhere in this region).

Good size Lake Trout can be found here as well as cutthroats, which can sometimes be found rising along the shoreline in the early evening.

Upper Section

This section of the Gros Ventre River is not quite as fast as the section below Lower Slide Lake but is otherwise similar in character. Overall the wading is still slightly on the rugged side due to the river fording and bushwhacking you’ll need, or want, to do from time to time.

The best water resides between the Gros Ventre River/Crystal Creek confluence and Upper Slide Lake. This entire section is public land and can be accessed at various points along the way via spurs leading off the main road down to the river. Wading upstream from the campgrounds (either the Gros Ventre or Crystal Creek will need to be forded) is also a good option.

Access to the Upper Section

From Jackson, drive north on Route 89/191 into Grand Teton National Park. Once in the park, take the first right (about 7 miles from town) onto Antelope Flats Road. Follow this road for about 1 mile past the Town of Kelly and take a right on Gros Ventre Road. Following Gros Ventre Road you will soon exit Grand Teton National Park. Continue on past Lower Slide Lake (the road now switches to gravel and dirt and can be rough at times), over Russell Hill (beautiful views), and past Red Hills Ranch. Soon thereafter you come to a bridge which crosses the Gros Ventre River. About a mile from the bridge are the campgrounds shown on the above map.

While normally fine for passenger cars, the gravel/dirt section of Gros Ventre Road can be very slick when wet, and may even be impassable. Waiting for things to dry out may be your best option if caught in a heavy rainstorm.

Hatches

Caddis in size 14 and yellow stoneflies in size 10 from late June through mid to late July. Then the usual hopper scene for the rest of the summer.

Flies

Elk Hair Caddis, Stimulators, Trudes, Jay-Dave’s Hopper, Tarantulas. HOT TIP: Humpies (red, yellow or royal, sizes 14-10) can be deadly along this stretch of river. Also, put a spilt shot on and fish the Humpy like a nymph…very effective!

You can also nymph the abundant pocket water with large rubber legged nymphs like George’s Brown Stone Rubber Leg Nymph, Yuk Bugs and Bitch Creeks (or, and I’m not kidding, Double Humpies).

Crystal Creek

About 1 mile after passing the Crystal Creek Campground you’ll come to a small bridge which crosses Crystal Creek proper. You can walk up from the campground or fish downstream from the bridge. Upstream from the bridge is private property. 150 yards or so past the bridge take a right like you were heading towards Red Rocks Ranch. Where the road forks, bear left up a rugged dirt road which is impassable when wet. At the end of the road is a small parking area and kiosk.

Note: If, after taking the right leading to Red Rocks Ranch (but prior to bearing left at the fork), you encounter a large No Trespassing sign. Rest assured you are not trespassing as long as you bear left when you come to the fork in the road. Hopefully by now, the location of the sign has been changed, but too many times in the past we have encountered Wyoming ranch owners attempting to intimidate law abiding citizens from accessing public lands which may border private ranch land.

At the same time, we realize that some people will end up trespassing onto the ranch property. However, we do not feel this justifies misleading and attempting to intimidate the public. We do not advocate trespassing on private property, but we will also, to the best of our abilities, make it a point to inform the public where their lands reside and how to legally access them.

Anyways, from the kiosk/parking area there is a short stretch of public land along Crystal Creek which extends downstream to the ranch, which is bordered by a fence. Cross the fence and you are trespassing. Everything upstream of the fence is public.

From the parking lot you can also ford Crystal Creek and follow a trail upstream for about a mile to a nice meadow. Do not be tempted to follow the old trail which leads upstream from the parking lot without crossing the creek. The trail, which leads into a steep, narrow canyon soon becomes washed out on very steep slopes with gravel acting as ball bearings. Furthermore, the soil composition consists largely of clay. This trail is treacherous and should be avoided. You may have made it up this trail a long time ago, but such is no longer the case.

Comments: Hoppers are the number one food source most of the time. Make sure you’ve got plenty of hopper patterns and Tarantulas.

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