Except for rivers controlled by dams and thus the water flows, most of our rivers systems are now lower than average and the fishing on most is pretty darn good. As a result, hatch activity and fish catching localities become much more specific to one's success. Where you are and when you're fishing are now very important. Let's take a look:
SILVER CREEK—Trico is still the main player but it's not universally seen in huge quantities. The floating sections have been workable but somewhat weak compared to areas where a slightly more water velocity is apparent. This situation is occurring throughout its length. Regardless, Dave's Trico Spinner #22 or Cut-Wing Trico Spinner #22 will do the job if Trico is present. Beatis is significant in the morning and a Mason Quill Beatis Spinner #22 and Sparkle Dun Beatis #22 work nicely. Missing are the morning spinners of PMDs but I have had solid reports that the spinnerfall is being seen in the evening, from 7 p.m. on. Afternoon is a time to be throwing Hopper imitations, especially in the lower reaches of the stream.
BIG WOOD RIVER—Fishing very well but now flowing below its "mean" average for early August. Again, success is a case of where you are and when you're fishing. In my experience, the further south you go on the river, the better production you'll have. Fly patterns are simple with Para Adams #16-18 and Purple Haze #14-18 doing the greatest damage. It's not a great Hopper stream, but fishing Hopper patterns #10-14 can move some good fish. Prince Nymphs #12-16 and Zebra Nymphs #14-16 are also effective.
WARM SPRINGS/TRAIL CREEK—Both are fishing but getting low in volume which makes for limited locations to find fish. Standard patterns in small sizes will move fish above and below the surface.
BIG LOST DRAINAGE—Honestly, the upper river (Copper Basin, North Fork, East Fork) has not been fishing well. It's now quite apparent that constant hatchery fish supplementation is needed for success. This comes as a great disappointment, for my greatest hope was that the Cutthroat Trout introduction a few years back would take and a new wild trout fishery would emerge. Not so. But then again, not really a surprise. If you knew what the 1970s and early 1980s were about, it will explain why there are tears falling on this page. Despite this, the lower river has been fishing exceptionally well. A bit higher than I'd like to see, nymph fishing with Prince Nymph #10-12, San Juan Worms and Black Griddle Bugs are moving some great fish. Because morning Trico is heavy in the quieter margins of the stream, good surface activity can be found.
PENNY LAKE/LAKE CREEK/GAVER'S LAGOON (HAYSPUR)—Always supplemented with fish. Fishing nicely using bait and flies.
SOUTH FORK OF THE BOISE—Still flowing at 1850 cfs which translates into floating the river for best success. Fishing various Hopper imitations and "Look-a-Likes" plus Pink Albert's #14-16 will find fish.