Dogs are allowed on Idaho Mountain Recreation trips at the discretion of the trip leader.
Several of our trip leaders regularly lead hikes with dogs. If the trip does not explicitly say "no dogs" ask the trip leader, and in most cases canine companions are welcome.
Snowshoe trips with dogs are less common. For one, a number of the local nordic facilities do not allow dogs on the trails. Second, dogs have a penchant - especially in deep snow - for stepping on the backs of snowshoes. While I personally don't mind because I love their company, I haven't taken my dogs on group trips for this reason. Dogs or no dogs is always at the discretion of the trip leader.