When a visiting relative wanted to sample Idaho's fabled fishing a month later, I assured her we could easily load up on perch at Cascade that weekend. Yeah, you guessed it. After a full day of trying every trick I knew, we went home skunked!
That isn't the only time Idaho's "easy-to-catch" yellow perch have taught me a lesson in humility. Perch fishing from one end of our state to the other is commonly a boom-or-bust proposition. These teeming little school fish have a knack for hiding out in the depths of the large reservoirs they typically inhabit. If you find a roving school (or it finds you), everybody hauls 'em in faster than they can bait a hook. If you don't hit a school or two, well, trout, bass, or catfish generally live in the same waters.
This state of affairs is unacceptable. Perch are one of the best-eating fish in fresh water. When you get into them, the wild non-stop action is delightfully free of piscatorial finesse. I want to be able to fill my freezer with delicious perch filets on demand, and I've given several years of research and experiment to learning to do just that. Here's what I've picked up so far on locating deep-water perch:
To start with, perch aren't always deep-water fish.
Particularly from early April to mid-May, or when water temps first hit 45 to 50 degrees, big perch move inshore by the thousands to spawn. Many of these fish swim up feeder creeks, most of which are still closed to fishing in trout-happy Idaho. The majority of perch spawners, however, deposit their long strings of 10,000 to 75,000 eggs at night directly on sunken weeds and brush in just a few feet of water.
This spring spawning period is said to be the only time of year you can catch lots of perch "jumbos" in shallow water. Since schools have broken up somewhat for spawning, try random mid-day shore walking (perch don't feed at night) while casting to deeper water near sunken weeds.
Perch will hit small lures like jigs, spinners, and spoons, but bait is usually far better - worms, cut-bait, preserved minnows, grasshoppers, shrimp, crawfish, etc. Where legal, fishing in or near the mouths of tributary streams is especially likely to put you into spring perch.
As spawning is completed, adult perch begin retreating to their more usual deep-water habitat - say 15 to 25 feet down with water temperatures around 70 degrees. If you're shore-bound try early-summer fishing about 15' deep on steep gravel points (not coves or ultra-rocky banks) where perch move in to feed especially in late afternoon. If the lake is very clear, fish deeper; if murky, cast less far out.
Perch will pick up baits directly off bottom, but suspending your worm or about one-half inch cube of cut-bait a foot or two above concealing rocks and weeds will help cruising fish locate it. Shore-bound bottom anglers can do this with a conventional trout marshmallow or a miniature steelhead drifter above the hook. If the bank is steep enough, a couple of dropper hooks (size 2, 4, or 6) above a terminal sinker will keep your baits fairly suspended.
Big perch in particular rarely suspend far above bottom, so you can generally forget surface and shallow bobber fishing except for shoreline peewees. Incidentally, the very biggest perch tend to dwell in the deepest water, medium fish at moderate depths, etc. and in schools of 50 to 200 fish which are mostly all about the same size.
For more serious perch chasing, a boat provides considerable advantage, especially during summer when larger fish are tightly schooled 30 to 50 feet down. Random drift fishing is fairly effective in locating deepwater schools. Use a light line for quick sinking and minimal water resistance, a fairly heavy terminal sinker, and a couple of dropper hooks spaced one to two feet above. Fish directly below your boat as it is pushed gently by the wind. "Hop" your bottom-tapping sinker along, which causes baits to flutter visually. Use shoreline topography to suggest underwater structure - if you hit perch over rocks, drift-fish near rocky banks. If fish are frequenting flat-bottomed weed beds, try to estimate where you'll find more weedy bays, and so on.
Important: once you hit an off-shore school drop a vertically-anchored marker buoy immediately. Summertime perch are often too deep to anchor over, and you're certain to lose the school if you don't mark it. Fishing buoys can be bought commercially or made from a flat H-shaped block of Styrofoam wrapped with a hundred feet or so of mono and a heavy sinker. (Round buoys won't mark fish vertically, since line keeps unraveling as wind and waves push the anchored buoy over the surface.)
If you can't find perch on your own, try "following the crowd," or try a fancy-dandy fish-finder. On known perch reservoirs, small flotillas of anchored boats usually indicate perch concentrations (or maybe kokanees) below, not well-scattered trout or bass. (Binoculars are handy for this kind of butt-insky fishing.) Actually, sidling up to a floating crowd of perch anglers isn't as presumptuous as it might be with steelhead or other glamour-species. There's usually a lot of boat-to-boat talking anyway, and several boats can keep roving perch schools located better than one boat alone. Just keep it quiet and don't push too close. One lady we heard about repeatedly casts huge sinkers "by accident" into any boat that crowds her.
Fishing sonars are one of the best ways of locating deepwater perch. Perch enthusiasts in particular who haven't yet joined the angling electronic age should seriously consider saving enough marbles to invest in a quality fish-finder. Sonar principle is simple: cone-shaped pulses of sound are shot vertically downward in frequencies varying from one to dozens of times per second. The sound bounces off suspended underwater objects (fish) as well as bottom rocks, mud, stumps, etc. and returns all this info to a liquid crystal display screen. Deepwater perch are easily spotlighted by these great devices even at extremely fast boat speeds, which means you can scout a lot of empty water in a hurry!
Whether or not you have a fish-finder, two other information sources should be tapped to help find deepwater perch. One is simple local inquiry with sport shops, boat docks, game department officials, and other anglers. Certain lake areas seem to concentrate perch for one reason or another, and earnest asking may put you directly above, or at least close to, such hotspots.
A final guide to promising perch waters is underwater topo maps or charts, if you can find them. May is an awful month in which to start thinking about winter ice fishing for perch, but next January remember to look for perch fishing crowds or at least abandoned ice-fishing holes.
From tiny ponds to enormous reservoirs, perch are well distributed in Idaho. These many waters are constantly changing as to their prevailing sizes and numbers of perch - from badly stunted swarms of 5-inchers to pound-plus jumbos like the 2 lb, 9.6 oz., 15.5 inch state record taken from south central Idaho's Wilson Lake in 1976 (in January!).