Sylvan Lake is stunning! The campground is popular, and people can reserve sites ahead of time by a year so you might not be able to depend on getting a spot the day you arrive, plan. I have been to Sylvan Lake twice in the past two years, and it was busy both times. There are many families at the campground and lake. When I was at Sylvan Lake this June ('18), the water was closed due to bacteria levels, which was disappointing. A nice swim after three hot days of backpacking would have been nice. The trail to Harvey Peak isn't far from Lake Sylvan. If you don't enjoy crowds and you are a hiker; I would suggest camping on one of those trails. Campsites need to be a certain distance from the Peak otherwise people can set up tents anywhere.