Compared with elsewhere in the province, accommodations in Banff Town are fairly costly and, in summer, often hard to find. The old adage of the early bird catching the worm really holds true here, and booking ahead is strongly recommended.
The Banff/Lake Louise Tourism Bureau tracks vacancies on a daily basis; check the listings at the Banff Visitor Centre. You might also try Enjoy Banff, which books rooms for more than 75 different lodgings.
Camping in Banff National Park is popular and easily accessible. There are 13 campgrounds to choose from, most along the Bow Valley Parkway or near Banff Town.