Henrys Fork Boat Access Map
Sections of the Henry’s Fork
We typically break the Henry’s Fork into a few different sections. Here are the sections with a Boat Access Map at the bottom.
Officially, the headwaters of the Henry’s Fork is located at Big Springs, it produces 120 million gallons of water each day. There are sections that are closed to fishing, but, most anglers will fish around Mack’s Inn and Coffee Pot Rapids.
Just below Island Park Dam starts the Box Canyon section, it ends in Last Chance just a few hundred yards away from our Island Park Fly Shop. Box Canyon is narrow pine lined canyon that is littered with rocks. It can go from 100 feet at the widest to about 50 feet at the narrowest sections. Stoneflies, Caddis, Mayflies, Midges, Terrestrials and all kinds of streamers work in different times of the year. Nymphing is the most popular and most effective technique in catching fish in Box Canyon.
Harriman Ranch – a.k.a. Railroad Ranch
There is 6 miles of river known as the Railroad Ranch or Harriman State Park in the Island Park area. The Henrys fork slows way down into a wide open high-country meadow with the majestic Centennial Mountains to the northwest & the Teton Range peaking out to the southwest.
The setting is breathtaking, but the dry-fly fishing is what really makes this place special. Let me just name a few hatches that are on the Railroad Ranch (as well as the rest of the Henrys Fork): Midges, Caddis, Golden Stones, Salmonflies, Yellow Sallies, PMD’s, Mahogany Duns, Brown Drakes, Gray Drakes, Green Drakes, Speckled Spinners, BWO’s, Flavs, Tricos, Dragonflies, Damsels, Ants, Beetles, & Hoppers. All of those in 5 months.
For those of you that care or just want to know a brief history of the name. The land was owned by Union Pacific investors from 1902 until 1977, it’s main purpose was a cattle ranch and private getaway for the Harriman & Guggenheim families. The Railroad Ranch, a total of 22 square miles, was donated for free to the State of Idaho & opened to the public in 1982. Now you know why it’s called the Railroad Ranch.
Mesa Falls Byway – (the Canyon)
Fly Fishing the Mesa Falls Byway (Highway 47) is for you folks that want to try something different, explore, or just get away from the crowded sections in Island Park. There are several wood roads that head west along the highway, meandering throughout Targhee National Park. Osbourne to Riverside is a really fun section to float in a drift boat, but be aware that it’s really challenging (towards Riverside) for anyone on the oars. You can hike down the canyon sections and fish the river in relative solitude, explore Mesa Falls, check out Warm River (a tributary of the Henrys Fork), then work your way to Warm River, then fish the amazing section down to Ashton.
Once we reach Ashton Reservoir the Henrys Fork flows through fertile farmlands with the Grand Tetons overlooking your every move. Just a couple miles west of Ashton (E 1300 N) is the Ora Bridge Boat Access. The Henrys Fork flows close to the road, so if you’re wading, it’s pretty easily accessible through Vernon, Chester, and on the way down to the Fun Farm Bridge.