Merlin Lake is a 21 mile lightly trafficked out and back trail located near Lake Louise, Alberta, Canada that features a waterfall and is rated as moderate. The trail is primarily used for hiking, trail running, camping, and backpacking and is best used from June until September.
Getting to the trailhead involves a 7.5 mile mike to Skoki Lodge, over Boulder and Deception Passes, from the Temple Lodge trailhead. If you are not a Skoki Lodge guest, you would have to begin at the Fish Creek Parking lot, adding 2.4 miles of hiking up the Temple Fire Road. These start points are both accessed from Whitehorn Road, which leads to the Lake Louise Ten Peaks Lodge from Route 1 (Transcanada). This is, therefore, NOT a day hike unless you are staying and Skoki Lodge or the Merlin Meadows campground.
My wife and I took this as a day hike from Skoki Lodge. There, the manager described it as an easy hike. I have to admit, it would have been easy, or at most moderate, if I didn't have bad knees, and my wife didn't have knee replacements.
We started in a rapidly melting 1/4" of snow from the night before. The hike across the rocks at the Wall of Jericho was easy for me, but a challenge for my wife, who had to pick her way very carefully. As we spotted beautiful Castilleja Lake below us, we also spotted a pretty, wooded trail beside it. We decided that we must have missed a trail junction, and had taken the wrong route - Wrong! We agreed to scamble/butt-slide down the rockslide to the other trail - about 1/3 mile. At the bottom, we set out on the nice trail, only to find that it soon ascended steeply and joined the higher trail we had left!!!! To make matters a little more worrisome, it started to snow - Thankfully, it didn't last, and it didn't accumulate (A group of "real" hikers who started with us, quickly outpaced us on their way to Merlin Ridge. They returned almost an hour after us (Odd considering our lengthy detour), and were turned back from the ridge by the same snow we hiked through - and through which we could clearly see the ridge).
After a brief snack, we continued on to a rock step about 4' high. Not a real strain for me, but it was tricky for my wife to figure out how to position herself to get up with fake knees. We then confronted the short, narrow ledge we had been told about. It wasn't too bad except that I have some issues with heights that mad the crossing interesting. A short hike then brought us to scenic Merlin Lake, surrounded by the Wall of Jericho and the Merlin Ridge. After lunch, we sought the green sign we had been told to find for a return via Merlin Meadows. It took only a few minutes to find the sign and trail cairns.
The trail was, as we had been warned, a sometimes steep, nearly continuous drop of 492', over about 2 miles to the meadows. After crossing a log footbridge, we found that the meadows were very boggy, and our boots were soon soaked. We spotted the white sign we had been told to look for on the other side and made our way to it.
The map we had been given indicated that Skoki Lodge was just past the meadow. In fact, the sign informed us it was another mile, and we discovered that it was a 210' climb! Thank goodness for the log bench overlooking the ravine, where we could rest, so that we weren't limping and so bedraggled looking after our adventure! Also, we got to see a very interesting woodland croquet set, with ramps to guide the balls over the very uneven ground. It gave us a good laugh that carried us back to the lodge.