My wife and I have done a lot of hiking on multiple occasions in Banff, Kootenay, and Jasper National Parks and a lot of hiking in near-by (to Banff) in Peter Laugheed Provincial Park, which is a gem located in what’s collectively known as Kanaskis Country. The hiking and wildlife were so good that fishing was secondary. Be aware that you are in grizzly, black bear (often cinnamon colored) and mountain lion country, and give elk and moose respect too. They’re not farm animals despite their docile appearance.
I only fished the glacial wash rivers (in that area mentioned above) of Kootenay and Bow for a few evening hours since they were next to our tent campsites and had no success, which wasn’t surprising given the turbid appearance, flow, and braided habitat. Can’t beat the scenery though. As you might expect, however, I have a keen eye for good habitat and water, and given time I would have inspected the Highwood River. I saw much of its length and it all looked fishy. I knew nothing about it when I first saw it, but it looked like “THE PLACE” to start. I later ran into a biologist who was working on a Bull Trout project, which then gave me even more encouragement if, in fact, the river was open to fishing. I just now briefly looked it up and I saw that there is a guide service featuring multiple coldwater species, so apparently there is a fishery. Recommend you investigate. Also, from what I saw, without knowing much about regs and landownership details, etc, it looked good for DIY.
As for the hiking, how serious are your traveling partners and you about hiking, or are you strictly interested in more typical American family “tourist hikes?” Eight to thirteen mile hikes, which will keep you on the trail for most of each day due to the quality of the scenery, wildlife viewing, just hanging out at a view or lake, and steep terrain if you want to get great views. We only ever hit one crowded hiking trail in the region, the Beehive hike along Lake Louise, a real tourist spot but should not be missed, and up onto some higher terrain. It was easy, but longer than the usual 1-3 mi tourist hike. There is also a tougher one, rated as “difficult” that starts at the lake. Great view at the top plus soaring golden eagles when we were there.
By the way, I’m not slamming tourist hikes; they take you to some very scenic spots and along rushing waters at times. We often saved them or a series of them for leg muscle recovery days and the ones in lower elevations through canyon scenery for cloudy days. We wanted to be up in the mountains on clear days.
In general in the region, if you hike in more than two miles you’ll shed the crowds. Also, starting a hike at a trailhead by 8-8:30 AM will also get you ahead of the crowds and help you see a lot more wildlife before everyone else disturbs it.
As for another tourist location that you shouldn’t miss, see Moraine Lake in the Valley of the Ten Peaks. Despite there being a lot of tourists at some locations and on shorter “tourist hikes” the scenery is so good that you should not let the tourists turn you off. Just get there early to beat a lot of them. The only hikes we did at Moraine Lake two very good high country day hikes that may have been rated “difficult.”
In all cases in the region, be sure to carry appropriate clothes and rain gear (pants and jacket, gloves) in case weather suddenly changes in the mountains, which it often does, even for short duration t-storms. We started in shorts and tee shirts at times and in high country hit a sudden hail storm and strong wind. That wasn’t the first time, so be prepared and carry the gear in day packs.