Citadel Pass has gotten a lot more inaccessible since I hiked it in the summer of 1988. Back then, the Sunshine Village gondola operated during the summer, and on a schedule that made it possible to hike the more than 18 kilometres across the Sunshine Meadows to Citadel Pass and back before it closed down. Nowadays, theres a shuttle bus, but the last one leaves at 5:00 p.m. not quite enough time to hike to Citadel Pass and back unless youre fast and healthy. Which is a real pity, because this trail is fantastic stuff, and you dont want to turn around any sooner than you have to, and you dont want to rush.
Other than the climb up and down Quartz Hill in the middle, its relatively level going across endless alpine meadows along the continental divide. You cross the border twice before the pass, and you dont even realize it unless youre checking your topo map, or you meet a B.C. provincial parks ranger and suddenly realize youre not in Banff National Park any more.
The trail to Citadel Pass is the first third of the route to Mount Assiniboine, and you get a great view of that peak from the pass.