I have caught fish pushing the 20" mark and one or two that were maybe a bit over 20" I was told these fish are hold overs and are rare. All the big fish I have caught in that lake were at the far end, oppposite the boat launch. That is a long kick in my little float tube, I dont make it down there very often.
According to the WSFG web site, they planted about 6 thousand fry this year. That is about half of what they have historically dumped in.
I don't fish the Snake all that much, but have caught big fish all over the lake. There is a deep "hole" just a few hundred yards off the launch, part of the old creek bed, where you can often find a big one near the bottom. The area on the far shore, among the stumps often holds bigger fish along the drop off. It is also a fun place to fish as there are stumps, structure, and fewer screeming children. The Osprey likes this area also. My biggest? Yea, about 20" and the few that size do tend to be better looking fish in shape and fin structure so likely have been in for awhile. I am one of the believers that growth rates at the Snake are low and planted fingerlings don't do very well.
Trout don't spawn in lakes. They behave as salmon do. They live and feed in the lake but return to the moving water of rivers and streams to spawn, so most of the lakes we fish depend on stocking to maintain the fish populations. Lakes, however do present an opportunity for trout to grow rapidly due to the rich food supply.:ray1:
It's probably just a coincidence but I don't recall catching any fish at RSL smaller than about 9". I haven't fished it yet this year so maybe it's because in prior years, it was planted with larger fish. The largest fish I've caught there were about 16-17" which I'm guessing were triploid planters, not carryovers from prior plants. I've talked to enough guys who fish it regularly to know that there are carryovers, but they're quite infrequently caught.
Trout don't spawn in lakes. They behave as salmon do. They live and feed in the lake but return to the moving water of rivers and streams to spawn, so most of the lakes we fish depend on stocking to maintain the fish populations. Lakes, however do present an opportunity for trout to grow rapidly due to the rich food supply.
This is true to an extent but as a whole an oversimplification. Here's why:
First, some true trout (onchorynchus) do indeed spawn in lakes, but only when certain conditions such as fine gravel and other variables align. Most lake-dwelling trout spawn in lake inlet or outlet streams, where conditions are generally much more favorable. If a lake is spring- or runoff- fed (such as RSL) and has no such inlet or outlet streams, then it's unlikely its trout will be doing any spawning. Replacing those fish caught and killed by anglers or by post-release morbidity must then be accomplished by stocking.
Some char (salmo) such as brook trout readily spawn in lakes, so much so that the food supply in infested lakes can be quickly overrun by over-reproducing brookies. When that happens, the fish first outcompete any native true trout and eventually become stunted with big heads and skinny, snakelike bodies as they outconsume the available food supply.
Second, only some lakes have the rich food supply required to produce rapidly-growing, large trout. In Washington, generally such lakes are located in the Columbia basin or the eastern part of the state where water pH allows for rapid and prolific plant and insect populations. More plants means more insects which means more food to grow more and bigger fish.
On the west side of the Cascades, lakes, especially high elevation ones, are generally much less fertile (thanks to different pH and fewer dissolved solids). As a result, most westside lakes have much lower biomass than eastside ones and thus less food for trout. Less food means fewer fish growing to smaller sizes than their counterparts east of the Cascades.
Did very well today with an intermediate Rio tip. Fished structure (=stumps) with a countdown. Three over 18", a dozen over 12". Need to get down a ways to get away from the Osprey feed WDFG just put in. Had one Osprey take a fish 20' in front of the tube. Awesome! These appeared to be 5" to 6" mostly. Many tugs from the little guys, had one take an indicator. Did get one fish on a chironomid, just for fun.