The Yellowstone is the largest free-flowing river in the continental United States, and stretches over 670 miles from its headwaters in the Teton Wilderness before emptying into the Missouri River in North Dakota. This is a large wild river in Montana, that is best fished from a drift boat, although there are certainly opportunities for the wade angler at lower flows. The Yellowstone provides great fishing with nymphs, dries, and streamers and produces some of the largest brown trout in the state every year. Most of these brutes are caught on streamers, and this is another reason why we love taking people over to the ‘Stone. Due to the immense size of the watershed, the Yellowstone experiences a fairly extensive runoff beginning anywhere from early to late May. On normal years the river starts coming back into shape around the second to third week in July, but it is not uncommon for runoff conditions to persist well into August on years with larger snow packs. That said, we recommend floating the Yellowstone from March through May and again from post-runoff through November. We focus most of our guided fly fishing trips on the upper 100+ miles between Gardner and Big Timber, as the river becomes more of a warm water fishery below the town of Columbus, MT.