March Brown Dry Fly Pattern by Gary Morin

Eastern March Browns (Maccaffertium vicarium) are a spring mayfly that can be found in many streams throughout Pennsylvania. They are predominantly found in Central Pennsylvania's popular streams like Penns, Middle, Big Fishing, and others.

Once thought to be a separate species, Gray Foxes are a little smaller and look similar to the March Brown, but have been identified through DNA to be the same species. Some will tie a very different pattern for a Gray Fox pattern depending on the stream.

March Browns are one of the first large mayflies to emerge, starting as early as late April and going into early May. Unlike many other hatches, they will often emerge throughout the day rather than at an expected time. They offer a great evening spinner fall when returning to lay their eggs. I like a rather large Rusty Brown Spinner pattern when the time is right.

Here is a nice pattern by Gary Morin found on his YouTube Channel.