Daily emergences can last for a few weeks to several months depending on the drainage, water temperatures, and stream flows. Hatches typically begin in mid-June and continue through September. Western pale morning duns include two species—Ephemerella dorothea infrequens and Ephemerella excursions.
Dry fly enthusiasts will find their fair share of rising fish too. My favorite dry flies are #18 Mathew's Sparkle Dun, #18 Cannon's Snowshoe Dun, #18 Parachute PMD, and #18 Barr's Vis-a-dun. Fishing is improving by the day as water levels continue to recede. Look for excellent dry fly fishing to continue for the remainder of the summer season.