Months March, April, May

Hatches Midge, Caddis, BWO, March Brown, Salmonfly, Golden Stone

Temps Lows in teens, Highs in the 60’s – snow or rain likely

Flows 200-600 CFS out of IPR

Defined as the pre-runoff months – spring flows are easily wadable and offer great hatches. The exception being in late spring below the confluence of Fall River. Lakes in the area ice-off – cutthroats spawn.

Midge, caddis, and BWO start the season – followed by March Browns. At the end of the season on the Lower – Salmonflies and Golden Stones begin to appear. Spring is also an excellent time of year to swing streamers.

March and April rainbow trout are spawning – so be mindful of where you step and avoid redds.


Months June, July, August

Hatches Caddis, BWO, March Brown, Salmonfly, Golden Stone, Yellow Sally, PMD, Green Drake, Brown Drake, Gray Drake, Flavs, Trico, Terrestrials

Temps Lows in the 30’s, Highs in the 80’s – likely dry

Flows 600-2,000 CFS out of IPR

Summer officially starts when the Harriman Ranch State Park opens to fishing on June 15th.

Salmonflies arrive at the end of May or first of June. They’re followed by a factory of caddis and mayflies that make the Henry’s Fork famous. By mid-July – terrestrial fishing starts to round out a very fishy season. Lake fishing heats up in July.

Flows are directly correlated to irrigation demand and the previous winter’s snow pack. Regardless the specifics – you’ll see flows ramp up considerably from spring and peak in July before beginning to fall again.

This is also – by far – the busiest season on the Henry’s Fork. Be courteous at the ramps and on the river and please pack it out!


Months September, October, November

Hatches Terrestrials, BWO, Tricos, Mahogany Duns

Temps Single digit lows, Highs in the 50’s – snow or rain likely

Flows 200-800 CFS out of IPR

Crowds wane and temperatures cool. Elk bugle and leaves change. Fall in the GYE is a magical time! Note that Harriman closes to fishing through June on November 30th.

Flows drop considerably from summer making wading much easier – and reopening access to areas you can’t get to in the summer.

Terrestrials and mayflies continue to produce good dry-fly fishing through September. Streamers throughout fall can be very effective.

Browns spawn in October – be mindful of where you step and watch for redds.


Months December, January, February

Hatches Midge

Temps Negative lows, Highs in 30’s – snow likely

Flows 200-400 CFS out of IPR

Island Park gets an average of 16 feet of snow each winter – making it a snowmobiling and XC skiing destination. If the snow and cold don’t deter you – there’s some great fishing to be had. Flows are low – making wading easy and holding water obvious. Hatches are limited to midges – but sub-surface a multitude of nymphs and streamers will produce.

Want More?

Every season offers a unique experience within the Greater Yellowstone Ecosystem. Come by the shop or book a guided trip to explore all the area has to offer!