Might be a rudbeckia... I also thought possible petunia or forget me not...
Of course, there are the weedy borages like Hackelia...
Unfortunately, the Montana climate is so much different from around here that I can't rule stuff out based on the season...
Around here, most of our blackeyed susan and forget me not would have already played out from the heat...
The leaves look to fuzzy (to me) to be Talinum (jewels of opar).
