The Metolius River in Central Oregon is a tributary of the Deschutes drainage. It emerges from under Black Butte as a fairly large spring creek, but this is only the start. Many other springs feed this river from an underground aquifer for the next ten miles. At Bridge 99 (8-miles downstream from the source) it is a full blown river. By the time it merges with Lake Billy Chinook 28.6 miles from the headwater source it has passed through a steep rugged canyon, and is a raging torrent of aqua blue water turned to white water. At Lake Billy Chinook, the Metolius (about 1,500 cfs) or about one third of the average summer flow of the Lower Deschutes River. The Metolius averages between 47 and 45 degrees in water temperature, and is nearly the same year around. For this reason it is the perfect trout habitat for the entire year around fishing season. All of the trout are wild. Redband Trout and Bull Trout are native. There is also a self-sustaining population of Brown trout which were introduced in the early 1900's. All of the river is regulated as catch and release with barbless hooks. About a third of the river is designated as fly fishing only. On the last trip, Patty and I took a number of rod/reel combos with us, and we used several, but we both settled on our Sage 590-4 X rods and Abel Creek Reels. They were the best for fishing for Redband Trout with either wet or dry flies.
The Metolius is famous for dry fly fishing. Hatches are seasonal, but because of the stable water flows and temperature some hatches are nearly year around. Baetis and Pale Morning Dun type mayflies are available nearly every day. So are many sizes of caddis and stoneflies. The coldest days of winter may be an exception, but even then there are often rises to tiny mayflies and midges. The fall months bring many hatches nearly every day during banker’s hours. No reason to be on the water before nine in the morning. Hatches for many parts of the year are over by five in the afternoon. Sizes of insects vary greatly from giant two inch stoneflies to tiny mayflies, caddis and midges. Key hatches are Salmonflies, golden stones, olive stones, yellow sallies, winter blacks, caddis run the whole gambit from giant orange fall caddis, cinnamon caddis, speckled wing caddis. The Metolius is the best mayfly river we have fished in Oregon, with green drakes taking the show in May, followed by pale morning duns, pale evening duns, and baetis mayflies nearly year around. You better come with well stocked fly boxes. These wild trout can be maddenly selective, leader shy, and can spot less than perfect presentations.
During October and into November masses of Kokanee Salmon (land locked Sockeye) migrate upstream from Lake Billy Chinook to spawn in the Metolius and its larger tributaries. Literally the whole river bottom where smaller gravel is allowed to collect gets plowed by myriads of pairs of spawning kokanee. This makes the bottom of the river loose so that aquatic insects have many places to hide and prosper. This fact has to contribute to proliferation of the afore mentioned hatches. These spawning fish also contribute directly to the trout food as well, because of the millions of drifting eggs that emanate from the spawn. We fished Glo Bugs to many trout that were stationed downstream from the spawning salmon. Every one bit the fly the first time it approached them in a natural fashion. We also found that they could often spit out the fake egg so quickly that there was never a chance to set the hook. Only one of the larger egg eating trout was fooled more than once. I watched it eject my Glo Bug twice before I was able to time the set correctly. Then he simply ran under a submerged log and broke my leader.
A few kokanee still had enough life to also take the Glo Bugs. Most ignored everything except each other. When hooked there wasn't much wiggle left in the kokanee, and we left them alone. Kokanee die after they spawn and there is little doubt the kokanee carcasses fertilize the river with nutrients that fuel hatches and help grow lots of healthy trout.
The part of the Metolius that we fished is regulated as Fly Fishing Only. That means that external weight, such as split-shot on your leader is not allowed. However a weighted fly on a dropper above your Glo Bug is allowed. We tried various dropper flies, such as stonefly nymphs, weighted caddis pupas and so-on. A few fish fell for our dropper flies, but most of them were whitefish. The trout that were feeding near the bottom were pretty much locked in on the drifting kokanee eggs. The yellow belly mayflies that hatched during the early afternoon provided the best trout fishing. These flies are of the genus Cinygmula, and they are available most calm days during the fall.