The Diable River is a fairly wide mountain-fed freestone river with a expansive watershed which makes it very responsive to precipitations. During early spring in April and May, water levels can be at flood levels or very high depending on ice and snow melt as well as springtime precipitations. Water temperatures can also be less than optimal for trout this time of year and afternoons on sunny days present the best fishing opportunities. The months June and July offer some of the best water conditions with optimal temperatures and levels throughout the day. Prolonged precipitations do however affect conditions during this period. As water levels drop to their lowest levels in August and September, the features of the Diable river become much better defined and the slower pace of the currents offer the best dry fly opportunities of the year. Early mornings and evenings are the best fishing times but some good surprises are always in store outside these periods. The fishing season on the Diable extends to the end of November for bass and pike with trout on a catch and release only basis from mid-September.

Within the 15 kilometer fishing sector, the Diable River consists mainly of long stretches of pocket water, at times deep, with scattered but poorly defined pools. Streamers and nymphs are recommended for the most part with good dry fly opportunities after July. Caddis flies are abundant throughout the season with the most prolific hatches occurring in early June. There is also a good population of stoneflies with the best hatches occurring at the end of June. Mayflies are not in large abundance on the Diable, in terms of numbers and variety. Hatches are limited in size and duration with imitation or attractor patterns being the most consistent performers.

Smaller area streams and tributaries of the Diable also offer good spring-time fishing opportunities for brook trout and also for brown trout. Depending on the amount of precipitation during the season, these can offer good fishing into late July.

In the spring, area lakes provide the best fishing opportunities for surface action on brook trout, lake trout and on some lakes, landlocked salmon. Several area lakes contain good populations of bass, pike and muskie which present good fishing opportunities during the summer months when temperatures rise. Most can be taken on a fly. Personal boat access on area lakes is restricted and so fishing them may require the services of a professional guide or use of on-site rentals.

Basic fly patterns for the Diable:

Dry Flies:
Goddard
Elk hair Caddis
Royal Coachman
Royal Wulff
Adams
Stimulator

Nymphs:
Hares Ear
Helgramite
Prince
Kauffman Stone

Streamers:
Magog Smelt
Matuka
Mickey Finn
Hornberg
Muddler