If you're driving up the Lamar through Yellowstone, it's only a couple miles' of hike up to one of the meadows of Slough Creek, which by this time should be just about right for some nice dry fly work. Once you get up into those meadows, it's all native cutthroats, C&R. (It is mostly uphill, but the trail is well defined.)

Last time I was out there, I landed one that went an honest 18 inches (measured against my net) and probably closer to 20.

Do make noise for the bears.

fiery, dependable, occasionally transcendent