Freestones, Tailwaters, and Spring Creeks

A secret in fly fishing is understanding water types. I like to classify the rivers and streams into three categories: Freestone, Tailwater, and Spring Creek. Each water type should be approach with different angling strategies.

Freestone rivers- A freestone river is free flowing and not dammed. They are generally found in higher elevations. Clear water and large boulders are usually good indicators of freestone rivers. Examples of freestones in the Boise area are the N.F. and M.F. of the Boise, The South Fork of the Payette, and the Middle Fork of the Salmon. A large majority of the mountain rivers and streams in the Boise area are freestones.

Freestones are beautiful rivers to fish

How to fish them- Freestones usually have less aquatic insect life than tailwaters and spring creeks. Therefore, matching the hatch isn't as important. Because of the lack of food freestone trout must be optimistic feeders. When I fish freestones I like to throw dry flies behind boulders. Large breaks in the current are usually dynamite. I usually walk 25-100 yards between holes. I just focus on the best spots and skip the rest of the water. 

Advantages- Freestones are great for beginners, and a large fly selection isn't necessary to catch fish. They are often in beautiful mountain settings, and you usually have a lot of river to yourself.

Disadvantages- Spring runoff makes freestone fishing tough. They can also get dirty after large rain storms. Freestones are often swift so mending and drag free presentations are critical. Also less food means smaller fish.  

Flies- Dry flies such as small hoppers, beetles, stimulators, humphies, royal wulffs, and caddis work well. If you are nymphing copper johns, hares ear, prince nymphs, and rubber leg stoneflies usually work. Large articulated streamers usually aren't necessary. I don't streamer fish on freestones often, but if I do small wooly buggers work just fine. 

Tailwaters- Rivers below dams. Examples in our area are the S.F. of the Boise, Owhyee, S.F. of the Snake, Big Lost, and many more. Because tailwaters are fed by dams the water tends to have more nutrients (and therefore more bug life) than freestones. Matching the hatch is fairly important on tail waters. 

Note: Tailwaters usually the best water type for streamers

How to fish them- When I fish tailwaters I often think about water temperature. If the water temperature is really cold fish will move closer to the dam. The water coming from the bottom of the dam is often warmer than the water farther down the river (in the winter.) If the water temperature is warmer I try to locate faster oxygenated water. It is critical to pick up rocks and understand the bug life in a tailwater. Fish won't move our of their way to hit stimulators like they will on freestones. I always refer to a hatch chart, and I call a local fly shop before heading out.

Advantages- There is more aquatic life which means bigger fish. Runoff doesn't affect tailwaters as it does freestones. 

Disadvantages- A more diverse fly selection is necessary for consistent success on tailwaters. When dams release a large amount of water it can make fishing more challenging.  

Flies- Dry flies to include: terrestrials, blue wing olives, midges, parachute adams, and caddis are the minimum (note: if you can have emergers to match your dries you will be significantly more effective. Dropping an emerger below a dry if very effective.) Necessary nymphs are prince, pheasant tail, san juan worm, zebra midge, copper johns, and rubber leg stone fly nymphs. I would also carry wooly buggers in various colors, sculpin, and crayfish streamer patterns. Note: This is the minimum I would take to a new tail water. However, consult a fly shop before heading out. They will know specific hatches occurring at the time of your trip.   

Spring Creeks- The name is pretty self explanatory, but just to be clear spring creeks are fed by springs. Flows and water temperatures are fairly consistent and they often have siltier bottoms than freestones and tailwaters. You will also find more vegetation growth due to the silt. This plant growth provides an excellent environment for aquatic insects. Silver Creek and the Henrys (Harriman State Park) are famous spring creek waters.

How to fish them- If you ask veteran anglers where can you go in Idaho to get your phd in fly fishing they will most likely tell you Harriman State Park or Silver Creek. Spring creeks are challenging, but they often hold large trout. Be prepared to fish light tippets, make delicate presentation, and be ready for soft takes. Fish will often hold in one spot and simply open their mouth to feed. This means your casting and timing needs to be dialed in.

Advantages- Spring creeks usually have large fish. Spring creeks are also less likely to have significant water level changes during run off. Water temperature also stays fairly consistent.

Disadvantages- I wouldn't recommend them for beginners. Its very rewarding to
catch a large fish on a spring creek, but be ready to put in your time.

Flies- Lots of caddis and mayfly patterns. I would also add scuds and damsel fly nymphs to my box. Once again consult a fly shop and a hatch chart.


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