This has been the story on the Yakima for the past two weeks. Unfortunately the last few days mother nature added quite a bit of volume to the river and in addition we saw the clarity go down. Regardless, it is a great time of year to be on the Yakima. Beautiful, healthy-pre spawn rainbows are hard to beat.
...and, 'The Invisible, Imaginary and Important Skwala Hatch' is a great way to kick off the season
Family - Perlodidae - Sub Family - Perlodinae
Genus - Skwala Curvata and Americana or Parellela
"...The Skwala nymph becomes fairly active at around 38-40 degrees and the adults will generally hatch anywhere from the 42-47 degree mark. The nymph generally emerges in the late afternoon and into the evening.
Body length 1/2" ( abdomen and thorax), with antenna and tail - 11/4"
Long Tails 1/2"
Color- Tan to Olive Dun
Body length 1/2" (abdomen and Thorax), with antenna and tail - 11/4"
Long Tails- 1/2"
Color- Dirty yellow to bright yellow to dark/olive-black
Skwala - Fact or Fiction?
Some would say they don't exist and others say they are prolific. Neither is true. Then what is there importance? Why the big talk of the Skwala?
The Skwala Stone is a typical stonefly in that it prefers faster oxygenated water. As with most stoneflies the life cycle is one year and it survives as a predator by eating other aquatic insects. They are an important food source for trout for many reasons:
1) As active nymphs they are often found in the water/food column for the trout, being knocked loose and free drifting. This is especially true during pre-hatch periods when their movement activity increases dramatically.
2) They are also available to the trout as the female adult returns to the water to lay eggs.
3) On a windy day as the adult is blown on to the water, and;
4) As a spent adult that falls on the water to die.
The Skwala nymph becomes fairly active at around 38-40 degrees and the adults will generally hatch anywhere from the 42-47 degree mark. The nymph generally emerges in the late afternoon and into the evening.
The Skwala activity is strong beginning mid February and generally lasting until mid April. Certain years don't offer as good of dry fly opportunities as others; It would be fair to say that dry fly Skwala action in February is certainly a lower percentage occurrence than in March, yet it has happened and will most likely happen again. The nymph migration however is always a key factor at this time of year.
This is fishing folks. Things change and not everything is constant. Insects are cyclical, and every day is different. If I were to pick what would usually be the best adult Skwala weeks over the years I would have to say the last two weeks of March and the first week of April. During those three weeks three to four days will be optimal, 4-5 days will be good, and the rest of the days will be, fishing!
The Skwala is a very important hatch in that it is the first Big Mac, Double Quarter Pounder, Super Big and Tasty meal of the season. Regardless of how many adults there are, the fish know they are there. Fish make their living on eating the predominant insects and food sources of the season.
The Yakima is a success story. I started fishing the river in 86' and although it is a busier river now, as most are, the quality of the fish are as good or better. In fact there are some remarkably large resident trout in the Yakima river. It has been a fun river to evolve with. If you haven't experienced it, I suggest you do.