Dog Lake is a classic that we do multiple times per year up Millcreek Canyon. The destination isn't very glorious, it's more like a large mud puddle. But, the hike up is very pretty and just the right length for a quick hike that'll still give you a workout. More importantly on odd days dogs can be off leash and fetch in the lake to their hearts' content. It's 6 miles round trip if you go the long route, which starts on the south side of the big water parking lot. The steeper route starts on the east side of the same parking lot, and is only about 4-4.5 miles round trip. Elevation gain is 1520 feet either way. We went with our friend April's mom, it was a good time.