While working in Billings, we have taken our two younger children to Pioneer Park many times. This park is the real deal-perfect for any age. Play equipment that ranges from toddlers to teenagers (and even adults if you're so inclined). There is disc golf, tennis courts, plenty of room for walking/jogging/exploring. There is a stream that runs through the park. Very peaceful area.
The only down side would be that he park's awesomeness attracts a lot of folks. Weekends can get pretty busy; however, the play equipment is the busiest and there is plenty of room to find your own space.

What a beautiful day for a symphony in the park wonderful music great people splendid day. Highly recommend for a person visiting Montana in the summer

Went intertubing with the family. Very good time. Nice people, snow was good. Great afternoon with the family.

A delight to stroll through or sit by and watch others....the trees and grassy area are cool and inviting...