Updated 9 Oct 2026, 3:02 am EDT. Get alerts for Grass Lake
National Weather Service; National Interagency Fire Center; U.S. EPA CyAN satellite; Michigan DHHS; Michigan DNR. Weather, warnings, fires and satellite refresh when you open the page (checked at most hourly).
Michigan DNR survey, fetched 7 Oct 2026. Not for navigation.
632 acres · deepest 6 ft (measured) · shoreline about 8.3 mi · clarity about 5 ft
Grass Lake is the 4th largest of the 70 named lakes of 10 acres or more in Montmorency County. By Michigan DNR survey it is the 33rd deepest of the 36 with a measured depth. Its water is clearer than 15 of the other 58 lakes in the county with satellite clarity readings. Its shoreline measures about 8.3 miles along the state outline. About 38% of its area is deeper than 4 ft.
Ranks against Montmorency County lakes in Michigan hydrography, Michigan DNR lake surveys and Michigan EGLE satellite clarity; shoreline measured from the state outline. How we measure
1 public access site on Grass Lake.
Michigan DNR boating access, fetched 7 Oct 2026.
Average water clarity is about 5 ft (Secchi depth 1.6 m, satellite readings 2018–23).
Michigan EGLE satellite clarity, fetched 7 Oct 2026.
Michigan DNR survey; straight-line miles.
Grass Lake is 6 feet at its deepest point, measured by Michigan DNR survey. It covers 632 acres.
Yes. 1 public access site is listed: Grass Lake.