My wife and I spent a week in September in Jasper using our hotel as base for jaunts to the hiking trails and sights that abound in the Canadian Rockies. Jasper is pretty small, but has many decent places to eat and you can walk from one end of the "business district" to the other in about 30 minutes. The town is bult along the tracks of the railroad and you will see some long.... really long.... freight trains a couple of times a day. Via Rail's luxury passenger trains stop here. We stayed at the Bear Hill Lodge on the East side of town. The lodge has kitchens so we would shop at Robinson's a local supermarket for breakfast items and snacks. I'd stay there again easily!
After a day of hiking and sightseeing we would come "home", rest a bit then walk to dinner out in one of the many local restaurants.
We saw elk in town near the RR tracks. Also mountain goats (or are they sheep?) and coyote while driving around. Wanted to see a bear, but not a one showed up.
The lakes, rivers, waterfalls and Glaciated peaks are beautiful. The view from the Jasper Tram back on the town is spectacular.
A few "must dos" are walk Maligne Canyon from "5th bridge" to the Maligne Canyon Visitor center, take the Jasper Tram, watch a freight train pass thru Jasper at the train station, hike near Mt Edith Cavell, drive the Yellowhead Highway to Mt Robson in BC.