Green River tailwater trout settle into a steady fall pattern

What's next

Expect conditions to hold over the next two to three days. Flow and temperature readings from the three gauges sit close together, so no sharp swing is on the horizon. Cool nights should keep water temperatures at or below this morning's readings, which suits trout through the afternoon.

Plan the best windows around mid-morning to early afternoon. That is when small insects typically peak in fall. Per Reno Fly Shop (NV), cooler temperatures in late September had trout focusing on small bugs, including Blue Winged Olives and midges, with perdigons, zebra midges and thread-bodied BWO patterns on their suggested list. That is a different river, but the same seasonal shift applies to tailwaters. Overcast afternoons are often the best time for olives. Trout Unlimited's recent TROUT Tip on nymph weight is worth remembering with flows this size: add or remove weight until the flies tick bottom without hanging up.

A waxing crescent moon means little moonlight late in the evening, so dusk fishing should stay productive without much competition from bright nights. Check current flow releases before wading, since tailwater flows can change quickly, and review state regulations before keeping any fish.

Context

Mid-October is typically the transition from late summer to full fall on a Rocky Mountain tailwater. Water temperatures that have eased into the low 50s are on schedule for the season. Brown trout generally become more aggressive and territorial as fall progresses, and many anglers shift toward streamers and egg or attractor nymphs. Olive and midge hatches usually become the main surface opportunity as the days shorten.