Larch Valley is undeniably the most beautiful larch season hike in Canadian Rockies and although it gets very busy during the fall, we'd still recommend it (we personally go every year because this trail is simply hard to beat during larch season!).
At 9 km round trip and around 500 meters of elevation gain, it is a great family hike for kids who can handle a moderate climb and there's an option to extend it to Sentinel Pass.
To access the trailhead, you'll need to get to Moraine Lake which means you need to book either Parks Canada Shuttle or one of the private shuttles (we recommend Moraine Lake Bus Company).