If youÃ¢ÂÂre looking for a large and yet completely natural lake, then Grand Lake is the place to be in Colorado. This glacial lake is the largest natural lake in Colorado in terms of surface area, depth, and total water volume. The lake itself is gorgeous, but the scenery surrounding the lake is just as beautiful. The lake is situated in Rocky Mountain National Park, and so you can always look out over the waters and see gorgeous mountains rising up above the blue depths of Grand Lake. Anyone who doesnÃ¢ÂÂt have their own boat can rent or charter a boat at the Grand Lake Marina. So whether youÃ¢ÂÂre an experienced boat owner or looking to go out for the first time, Grand Lake is a fantastic boating destination.