Nobody's answered so I thought I'd jump in to try and help out. There is a fairly good sized RV Park in Canmore which is at the east entrance to Banff National Park, it's changed hands a couple of times since I stayed there about 4 years ago. Close to town or in it, on a pretty little creek and full service pullthru sites. Another spot further east may be at the new Indian Casino at Hwy 1 (TransCanada Hwy) and Hwy 40. I don't know if they do the overnight RV drycamping or not but they have a huge parking lot. The casino itself is on the south side of the highway so it's easy to see and easy to get to but again, I don't know if they have facilities or interest in parking RVs'. Just about every other casino does so that's why I included it.
Hope that helps a little,
1998 Volvo 610
2004 RE3 36' Mobile Suites (the Sweet Suite)