The Boulder River near Big Timber and half way to Billings is slowly on the rise but with the cold weather in the forecast, things will most likely drop and clear again. The water is still cold and many fish remain in the winter holds. They are a bit spooky but nymphing has been solid. Fly selection isn’t complex this time of year, with old standby’s like San Juan Worms, Girdle Bugs, and Pheasant Tail’s producing fish. Hatches are sparse over here in the spring and the cold, low water isn’t great for streamer fishing. Look for your deeper, slower water and you should be able to nymph em’ up.
If you do fish the Boulder River right now lengthen your leader and drop down a few tippet sizes for the best success. Even though the fish on the Boulder River are not pressured, fishing right now can be lot more technical when compared to other rivers in the area and more technical than one would think right now. The good news is that fish are in deeper water where they aren’t as nervous. This is a cold fishery so the best fishing has been in the afternoons. Baetis will start to produce in the coming weeks, but are just showing up.
Be sure to read our latest blog post on how to choose the best leader for fishing for trout: Choose the Correct Leader and Catch More Fish.
The Month Ahead:
The Boulder is a north facing drainage and tends to go into runoff a bit later than other area rivers. As the water warms and rises the fish will become more active and spread out. Nymphing is going to be the preferred technique until after runoff subsides.
Long Term Fishing Forecast:
Dry fly fishing will pick up on the Boulder as its hatches get going after runoff. Like the Gallatin, the Boulder has extremely cold water and tends to fish well all summer. Terrestrials become very important over here later in the summer.