Hellroaring Plateau Conditions

My wife, son, and I are heading out to Montana to visit the in-laws . We are planning on heading up to Hellroaring Plateau by way of Hellroaring Rd., and a couple of us would like to summit Mt. Rearguard. I'm aware of the rough road conditions, but am concerned there my still be a decent amount of snow up there or snow drifts in the road. Anyone been to the area yet this spring or early summer? Any information would be appreciated.