The Gardner River is a fascinating and diverse fishing destination located in the northwestern portion of Yellowstone National Park, beginning high in the Gallatin Range at an elevation of around 10,000 feet before flowing through various terrain until it joins the Yellowstone River near Gardiner, Montana. This freestone river offers dramatically different fishing experiences along its roughly 25-mile course, from small brook trout in its headwaters to larger rainbow and brown trout in its lower stretches. The river transitions from high mountain meadows through the dramatic Sheepeater Canyon with its 100-foot Osprey Falls, before continuing through arid terrain characteristic of the lower Gardner area, which is noticeably different than found elsewhere in Yellowstone. The lower Gardner is characterized by extensive pocket water with fast currents, numerous runs, riffles, and occasional pools, offering challenging but rewarding fly fishing opportunities.