....................... ......Fly Fishing Yellowstone National Park
Freestone Streams - Part 5
It doesn't take much to upset the balance of nature in a freestone stream. Many, many factors can do just that. The logging of timber has been a major problem for many streams. The construction of roads (even in Yellowstone National Park) has also affected many of the streams and in many different ways. The construction of lakes and reservoirs has also affected some of the streams. The list goes on and on.
For our purposes here, the main thing to be gained from these adverse affects is that anglers should be aware of what makes a freestone stream produce good trout fishing and what hurts them. Two important points to stop and register is water temperature (which also affects the oxygen content) and water levels or stream flows. Knowing these two things about a freestone stream is the first and primarily the most important things to know.
Water temperatures can be obtained from the information section of our "Perfect Fly" website. Under normal weather conditions you can expect the water upstream of that point to be slightly cooler. You can also guesstimate that other streams in the park near the same elevation are close to that temperature. By far the best source of information is the angler’s thermometer. It will provide water temperatures that are accurate at the time you are fishing at the particular point you are fishing.
Stream flows can be obtained from the same site linked above. Most of the time this will give you some indication of the water levels and stream flows on other streams in the park, but not always. Thunderstorms and melting snow that occurs in a different watershed can change that very quickly.
The next most important thing would probably be the clarity of the stream’s water. The stream levels and flow rates are good indicators of the water clarity but this information alone is sometimes deceptive. Of course, once you are on the stream, you can see the watercolor conditions for yourself.
The pH of the water is yet another factor that affects the trout and its food but it is one you can do little about. You can change the way you fish to adjust to water temperature and water levels but you can't adjust for high pH levels. Of course, just knowing the water temperature and level is not enough. The information is worthless if you do not know how it affects the trout and how it affects your fishing.