FIND THE HATCH
Tricos are clambering, slow-water nymphs that often favor the weedy, silty margins of large trout pools, rather than tumbling freestone water. Most American trout rivers that remain cold enough to hold active trout in August, meaning generally below 70 degrees, also have large numbers of tricos. Hatches are very predictable, occurring from about mid-July through some portion of September. Spinner falls, which concentrate the bugs in the greatest numbers, usually take place in the morning and are the most important phase to trout and anglers alike. For the past 20 years or so, common knowledge among anglers has been that spinner falls happen when the morning air temperature reaches 68 degrees. I've seen exceptions, but if you need a rule to follow, use that one.