The DNR is busy mapping aggregate resources across the state. But you might not realize how much aggregate like gravel you’ll need in your life. According to Chad Crotty, Aggregate Mapping Geologist from the Minnesota DNR, each person uses about 10 tons of aggregate per year. They’re busy mapping it for each county across the state of Minnesota, through the Aggregate Resource Mapping Program. “We do that by looking at mostly lidar, map landforms using lidar, soils maps, geology maps.