April 15th is the date in Montana where we transition from measuring snow to rain for our precipitation, so it's a good time to look at the current SWE (Snow Water Equivalent), in our watersheds and try to forecast what's to come in the next 3 months. We'll still get some high elevation snow in the next month (6 inches at Big Sky yesterday for lucky late season skiers!), but most of our precipitation will be in the form of rain from here on out. April, May and June are by far the three wettest months of our year in Montana, so we can expect some soggy days ahead, and we'll need them to make that solid snowpack pay off in late summer.
Aside from the Smith/Judith/Musselshell basin, we look to be in pretty great shape this year; 89-119% snowpack across western and central Montana is excellent and as long as we get near average rainfall and no early onset extreme heat we should be sitting pretty this season. We paid for it this winter with 2+ months of bitterly cold temperatures and way above average snowfall.
What does this mean for specific watersheds? Well, that is a bit harder to forecast. Some rivers like the Big Horn and Blackfoot are already running high. Most others are about average to a bit above and are fishing well for spring conditions. They are also providing excellent spawning conditions for our rainbow trout reproduction period, which bodes well for the long term health of our wild trout populations and fisheries.
We should expect a solid run-off period for all of our freestone rivers (Yellowstone, Gallatin, Clark Fork, etc.), and the potential for more intense but shorter releases on our tailwater rivers (Missouri and Bighorn).
If you like to fish lower/cleaner water and/or dryflies then the next month is an important window of opportunity for you. Midge, baetis and skwalla hatches are underway on many waters and the fishing is solid to fantastic. There will be a period of time around mid-May to mid/late-June where lots of our rivers should be in some state of run-off, so options will be more limited and you'll have to choose wisely for productive fishing.
There are no guarantees when it comes to water and weather, but as of today we like the layout of things to come and we hope for a nice 'average' year from here on out.