Print it. Bag it. Bring it.Phones die, screens crack, and most of this water has no signal. Print this map, fold it into a zip-top bag or dry bag with your license, and you have a backup your electronics can’t give you. Every marker is numbered so you can say exactly where you are.
| # | Point | Type | Lat, Lon | Notes |
|---|---|---|---|---|
| 1 | Big Springs Caribou-Targhee National Forest | Spring | 44.50057, -111.25496 | Source of the Henrys Fork - a large constant-temperature spring that starts the river at full size. |
| 2 | Big Springs Campground Caribou-Targhee NF | Campsite | 44.49753, -111.25448 | |
| 3 | Upper Coffeepot Campground Caribou-Targhee NF | Campsite | 44.49058, -111.36676 | |
| 4 | McCrea Bridge Campground Caribou-Targhee NF | Campsite | 44.46224, -111.40054 | |
| 5 | McCrea Bridge boat ramp OSM: unnamed slipway on McCrea Road | Access / boat ramp | 44.46141, -111.40159 | At the head of Island Park Reservoir; the usual take-out for the Big Springs and Coffee Pot water. |
| 6 | Island Park Dam Bureau of Reclamation | Dam / hazard | 44.41872, -111.39624 | |
| 7 | USGS 13042500 Henrys Fork near Island Park Real-time flow and stage | USGS gauge | 44.41667, -111.39472 | Check the reading before you commit to a float; releases and runoff move this river fast. |
| 8 | Boat ramp below Island Park Dam OSM: unnamed slipway on Forest Road 563 | Access / boat ramp | 44.41613, -111.39501 | Head of the Box Canyon reach. |
| 9 | Box Canyon Campground Caribou-Targhee NF | Campsite | 44.41019, -111.39605 | |
| 10 | Boat ramp at Last Chance OSM: unnamed slipway on Old Highway | Access / boat ramp | 44.37115, -111.40275 | Foot of Box Canyon and head of the Last Chance flat water. |
| 11 | Harriman State Park Idaho Parks & Recreation | Park / conservation area | 44.33603, -111.46135 | The Railroad Ranch water; park access is on foot from the park lots. |
| 12 | Osborne Bridge Highway crossing at the foot of the Ranch | Bridge crossing | 44.32472, -111.44859 | |
| 13 | Riverside Campground boat ramp OSM: unnamed slipway on Riverside Campground Road | Access / boat ramp | 44.26678, -111.45615 | |
| 14 | Mesa Falls Waterfall on the Henrys Fork | Dam / hazard | 44.18765, -111.32976 | OSM maps a single 'Mesa Falls' node here at the upper falls; the lower falls are a short way downstream. No boat passage through this canyon. |
| 15 | Grandview Campground Caribou-Targhee NF | Campsite | 44.17487, -111.31355 | |
| 16 | Boat ramp on North River Road Unnamed in OSM | Access / boat ramp | 44.10942, -111.33801 | Above Ashton Reservoir. |
| 17 | Ashton Dam Hydro dam on the Henrys Fork | Dam / hazard | 44.07850, -111.49687 | |
| 18 | Boat ramp on East 1300 North Unnamed in OSM | Access / boat ramp | 44.06995, -111.51054 | Below Ashton Dam. |
| 19 | Boat ramp on 2830 North Unnamed in OSM | Access / boat ramp | 44.01816, -111.58245 | Chester to Saint Anthony reach. |
| 20 | Boat ramp on South River Road Unnamed in OSM | Access / boat ramp | 43.98290, -111.62394 | Above Saint Anthony. |
| 21 | Boat ramp on North 1900 East Unnamed in OSM | Access / boat ramp | 43.92736, -111.77847 | Below Saint Anthony, on the run down to the Snake. |
Gauge: USGS 13042500 — HENRYS FORK NR ISLAND PARK ID. Live flow on the web page.
Species: Brook Trout, Brown Trout, Cutthroat Trout, Mountain Whitefish, Rainbow Trout
Regulations: idfg.idaho.gov/rules/fish
Emergency: call 911 and give the number of the nearest point on this map plus its coordinates.
Big Springs: the headwaters, a no-fishing spring with enormous visible trout.
Mack's Inn and Coffee Pot Rapids: upper river access above the reservoir.
Box Canyon: below Island Park Dam near the gauge, boat launch and walk-in access.
Last Chance and the Harriman Ranch: the famous flat water, walk-in from the state park.
Harriman State Park: parking, trails and seasonal access rules.
Riverside and Hatchery Ford: canyon access above Mesa Falls.
Warm River and Ashton: the lower river and the tailwater reach.
Late May through November on most reaches; the Ranch opens on a set date each June.
June: salmonflies in the canyon and green drakes on the Ranch, the peak of the year.
July and August: pale morning duns, callibaetis, terrestrials and technical flat-water fishing.
September and October: mahoganies and tricos, then streamers as the crowds leave; the Box fishes all winter where open.