Necro-post I know but...
This isn't completely true. Prairie sharptail? Yes. But Columbian Sharptail (also known as mountain Sharp-tailed grouse) can absolutely be found in the same habitat as blue or dusky grouse in the early season.
In south-central Wyoming you always need to be mindful you're shooting at a dusky and not a sharptail as there is no open season west of the continental divide. But the tail shape and color are a dead give away. Also mountain sharptails are a bit smaller than prairies (way smaller than dusky)
