For starters there are leeches in the water. I’ve swam with my children and the only way they’ve gotten onto them are when they go hunting for them. :) Denali outdoor center rents kayaks, canoes, etc right on the lake and are pleasant to work with. The lake is fun to paddle board, kayak/canoe on for the day. You can even catch stocked rainbow trout! There’s a small playground/picnic area. This is a wonderful backdrop for photos!
There are multiple little land masses throughout Otto Lake that you can kayak/boat to and camp. There is one small one in particular that doesn’t take too much effort to get to. There is a fire pit built in the center but make sure no one is out here before officially setting up for the night! Many locals like to go there for the day and just hammock or rest after kayaking. The price will be dependent on if you have kayaks or boats to get to the island. The lake is not deep and you could probably walk across to the little land patch if necessary. There are no restrooms and please please clean up after yourselves and others!