We are coming off a brutally cold February in the Snake River region. It may not have been a record cold month, but it has been below average. We are looking forward to what is generally the fun month of March, still fantastic skiing in the area, but also warmer days for fishing. In Jackson Hole, for example, daytime temperatures in March are on average nine degrees higher than in February. Days are getting longer, too. Yesterday I fished the South Fork in the vicinity of Conant Valley until 6:30 pm and there was still light for another 20 minutes or so. Watching the seasons progress from winter to summer gets most of us at Snake River Angler excited and eager about whats to come.
If you get out on the water over the next month, be prepared with patterns that will match chironomids, bwos, and little black stoneflies (Capnias). But also stay on the lookout for little green stoneflies (Chloroperlidae). The little green stone makes an early to mid-summer appearance on most trout streams in the West, but on the Snake and its tributaries, you will find them quite a bit earlier. You will see the come out just after equinox. The Lime Trude (size 12) and the Jimmy Z (size 10 to 12). Like yellow sallies, little green stones can emerge within a stream by coming to the surface and crawling from its shuck (hence the effectiveness of Howard Coles' Yellow Sally Emerger. Nonetheless, I find the Lime Trude and the Jimmy -Z to be most effective in the spring when fished along banks and structure and on slow-water flats. This is where you should target your little green stone imitations, as well as your little black stonefly patterns.
Trout Population Estimates for the South Fork
In Early February, the Idaho Department of Fish and Wildlife released the population estimates from the South of the Snake River. As we would expect from the most consistent trout stream in our region, trout abundance is strong - 4,618 trout per mile for the upper South Fork and 1,051 trout per mile on the lower South Fork. The number of cutthroat and brown trout on the upper South Fork are up slightly, while the number of rainbow trout are down slightly, suggesting perhaps that the Angler Incentive Program (i.e. - 0 limit on rainbow trout), tributary weirs, and the timing of freshet releases from Palisades Reservoir are having their intended impact. We take all of this with a grain of salt, however. we saw dramatic increases in the number of cutthroat over rainbows for a few years until 2010, when rainbow number suddenly jumped and overtook cutthroat numbers. Hopefully what we saw happen this year will start the same trend that we saw prior to 2010. Many of us believe that the key is the freshet releases from Palisades Dam - if these can be timed properly with the spawning of rainbows on the upper South Fork, we could see more impactful decreases in rainbow numbers and increases in native cutthroat.
Interesting Article about Idaho's Angler Incentive Program
The Jackson Hole New and Guide's Paul Bruun recently wrote a very insightful piece regarding the efforts on the South Fork to reduce the number of non-native rainbow trout. Go to this link to take a peek - http://www.jhnewsandguide.com.search.php/?date=2011-02-16
