Yes, absolutely!
We would appreciate if our guests could try dressy casual, while we know this is an elopement and we will be in nature we still have a vision for our special day. We will be outdoors so make sure you wear comfortable shoes, Montana weather can also be unpredictable so layers would probably be a good thought as well!
The bridal party has rented an air bnb, guests who choose to come will need to make their own accommodations. I would suggest staying in Bozeman, as it is the closest to the hyalite canyons. I will list some hotel recommendations, but you are more than welcome to do whatever is best for you and your family.