From this release on the MFWP website:
Upland game bird hunters who have been watching the weather won't be surprised that Montana Fish, Wildlife & Parks officials expect eastern Montana's pheasant and grouse numbers to be well below average this fall. In western and central Montana, game bird counts will be similar to or slightly down from last year. Upland game bird hunting begins Sept. 1. Pheasant season opens Oct. 8. The most severe winter conditions, including prolonged, deep snow, occurred east of a line that ran from north of Shelby to the southeast corner of the state--a vast area.
FWP officials said this extreme winter weather followed by a very wet, cold spring significantly reduced the winter survival and spring production of upland game birds. "Fortunately, western Montana counties avoided some of this extreme weather and hunters should find some upland game bird populations in western Montana that are similar to what they saw last year," said Rick Northrup Montana Fish, Wildlife & Parks game bird coordinator.