Also, be sure to check out our Perfect Fly Hatch Charts for streams in Yellowstone Park. . New "Perfect Fly" Website Stream Section - Middle River We just added a new stream section in our Perfect Fly website for the Middle River in Yellowstone National Park. This stream is located at the East Entrance of the park coming in from Cody, Wyoming.
One reason this area Is not fished very much by visiting anglers is that it's located in an area known for grizzly bears. You also have to pass up the Shoshone River to get there. It's a small stream but its well worth fishing. It is very easy to access because it's just off the road leading into the park although usually out of sight.
We have never seen another angler fishing this stream. You most likely will have plenty of space and water to fish. I would carry some bear spray anytime you fish this one. We haven't but we probably were not being very smart.
Both large brook trout and some very nice cutthroats are found in the stream. Browns move into the lower section from the Shoshone River in the Fall. Here's our four page section on the Middle River.