Fly Fishing: Brown Trout Streams
by
Eugene Macri

Fly fishing for brown trout in Pennsylvania and across the U.S. are of 3 major types: 1) freestone, 2) limestone spring creek, 3) limestone spring influenced.  Freestone streams are subject to constant water changes in temperature, turbidity and volume. Limestone spring creeks have a constant temperature range, little turbidity, and a relatively stable volume except in extreme conditions.

Fly fishing for these trout also involves 3 major population types: 1) stocked trout, 2)holdover trout, and 3) wild brown trout populations. In some instances all three populations may be found in the same stream or watershed.  There is a great debate about stocking hatchery trout over wild trout populations.  Scientific studies show this to be a problem but due to political pressure and a poor understanding of aquatic science state agencies often fail to take the proper scientific approach that is needed.

Fly fishing for browns in freestone streams in most states consists mainly of stocked and holdover trout. Contrary to the belief as espoused by many websites, guides, fly fishing magazines and books there are a limited number of wild brown trout streams in the country of the freestone variety and their numbers are diminishing from over development, pollution, and poor land management practices. Freestone streams are usually of two types: 1) put and take streams and 2) holdover and sometimes wild populations.  Put and take streams are stocked heavily right before the season and usually the first few weeks of the season.  Many of the streams are actually marginal trout waters where the summer temperatures on any given day may be to lethal for trout. Some of these streams however, often have a few spring holes or tribs or a couple deep stretches which allow the fish to survive the summer.  Holdover populations are usually there for a reason: the environment allows them to survive.  Often times these holdover fish will spawn and produce a wild population in the stream.

Fly Fishing for browns in spring creeks is a different game plan all together.  These streams many which are similar to the English Chalk Streams produce the most selective and in some streams very large fish.  These streams have more constant insect hatches but not the variety of freestone streams. The insect hatches are often more intense and have a longer duration than on freestone streams. A good example of this type of stream would be the Letort (Letort Spring Run) near Carlisle, Pennsylvania. 

Finally, fly fishing in limestone spring influenced streams.  Some streams start off as spring creeks and then get larger on their way.  These streams will often have large number of insects and rich environment for trout.  Many times these streams will grow with tributaries and change their biogeochemistry along the way.  Many of these streams will contain all three populations of stocked, holdover, and wild brown trout. Some of these streams will contain all three in the same stretches of water!  Examples of such streams in Pennsylvania would be Yellow Breeches Creek, Penns Creek, and the Little Juniata.