Silverhorn Creek Campground is one of only two campgrounds with reservable sites on the Icefields Parkway. Both are pretty good but I think Rampart Creek is a little noisier and buggier.
There are 45 sites at this campground. Reservations open in January each year and are available via the Parks Canada website.
Please note that there is no drinking water at Silverhorn - the nearest fill-up point is Waterfowl Lakes Campground (only 5 minutes drive north).
A Parks Canada parks pass is required to explore Banff National Park ($22/day for a vehicle of up to 7 people).