Great Lakes and Great Times: Michigan boasts four Great Lakes, 11,000 inland lakes, 36,000 miles of rivers and streams, 20 million acres of forests, 100 state and national parks and recreation areas, 1,300 miles of bike trails, 6,500 miles of snowmobile trails, the second-most ski areas in the nation, 650 public golf courses, 600 campgrounds, and an international dark-sky park-just for starters. Two years of experience as a State Police Detective Sergeant or its equivalent may be substituted for the experience and education required at the entry level; three years of such experience may be substituted at the intermediate level; four years of such experience may be substituted at the experienced level, and five years of such experience may be substituted at the advanced level.