The Jefferson River is no longer on Hoot Owl Restrictions! Streamflows are still very low so plan your fishing accordingly. If you choose a long float, be prepared to do some pushing through the less fishy water and focus on the water that will hold more fish this time of year...and that water is shelfs below riffles, along banks--especially in foamlines and eddies, and in medium fast water that is at least 4 feet deep. If you choose a shorter float that means you can spend more time in the water that is likely to hold more fish. If you choose to walk-and-wade, be prepared to walk some to get from good spot to good spot.
Hatches on the Jefferson River right now are not strong so prospecting with hoppers or streamers is a good idea. However, the weed growth of summer is still thick which makes fishing streamers a little trying to the patience as stripping the fly means it collects weeds.
A tandem nymph rig will most likely catch the most fish right now. Use a large lead fly such as a Pat's Rubber Legs in size 10 and then a smaller beadhead like a PT or Perdigon in size 16 to 18. Even a larger Zebra midge could catch some fish right now.
The Month Ahead:
The Jeff in the fall can be a good option now that water temperatures are more trout-friendly. Expect some hatches of tricos and caddis in the morning, but not much beyond those two hatches. The further we get into September the better the fishing on the Jefferson should become. Have reasonable expectations for this smaller Montana freestone. Terrestrials will provide the bulk of the fishing action for dry fly anglers for the foreseeable future. For anglers who value quantity of fish caught over solitude, the Jefferson isn't a good option right now. Choose one of the fish-ful tailwater rivers like the Madison or Missouri.
Long Term Fishing Forecast:
The Jefferson will be an OK local option from now through November. However, with the low flows and warm weather of the summer, it may take a few weeks before trout in Jefferson truly get back into a regular feeding pattern.