I don't know if you're fishing for migrating fish like steelhead which are here one day and gone the next, but I'm kind of assuming you're after resident trout. One of my local rivers, the Metolius, was stocked for years. When they quit stocking the hatchery fish quickly disappeared and there were a couple years where wild fish were hard to find. Each year there were more fish, and it took about 5 or 6 years, but the wild fish repopulated the river in numbers that made fishing worthwhile. I hope that happens to your river, but it's dependant on spawning gravel, food, and a host of other conditions.