An official Path Through History Site! Moss Lake Preserve is designated as a national and natural landmark. The most outstanding feature of the preserve is its 15-acre bog lake, which was formed thousands of years ago. After the last continental glacier melted, it left behind a water-filled depression. Eventually, a sphagnum moss mat grew over much of the open water. Experience nature as you hike the trail around this nature preserve and lake formed from a glacier melt.