Waterton Valley Trail is a 20.3 mile moderately trafficked out and back trail located near East Glacier Park, MT that features a lake. The trail is only recommended for very experienced adventurers and primarily used for hiking, camping, and backpacking.
My wife and I were interested in a day of photographing moose, so we opted for the 2.5-mile section of this trail to Kootenay Lakes. We took the 10AM boat from Waterton, CA, down Waterton Lake, crossing the border into the US, landing at Goat Haunt. There, you find an International Peace Pavilion and restrooms. After clearing Customs (Yes there is a station there with a couple of very bored officers, and you have a passport), we started our hike. After a couple of well-marked trail junctions near the beginning, the trail is easy to follow. The inclines and declines are easy and minimal, as the trail rises only about 300' by Kootenay Lakes. There is one brief section that is notoriously buggy, but no issues otherwise. At the lakes, the trail becomes less clear. Just before the lakes there is an outhouse, When you reach the lakes, there are a couple of log benches and a couple of tent camping sites. The moose viewing at the lakes was as good as advertised - once the two couples with small, noisy children left. We spent a couple of hours photographing a mature bull, a younger bull, two cows and a calf. It was easily worth hanging around and missing one boat to take the next back to Waterton (If you miss the last boat, Waterton is a 7+-mile hike along the lake). Not a bad way to spend a day, getting back in time for dinner.