US lakes & pondsUS lakes & pondsSurface area: The USGS National Hydrography Dataset outline (NHD Permanent ID 44364468).
The red circle marks Thornton Lake.
Towns and counties: U.S. Census Bureau boundaries overlaid on the USGS lake outline.
Official Michigan DNR pages. Rules and fees change; check before you go.
Built only from the data on this page: official access lists, OpenStreetMap beaches and trails, campground listings, state and USGS invasive-species records. We don't rate crowds or water quality.
Source: Michigan Department of Natural Resources, Institute for Fisheries Research inland lake deepest-point data (lake 2-1). Lake depth maps are on the DNR inland lake maps page.
Numbers on the map match the list at rightbelow.
Shoreline: USGS National Hydrography Dataset (NHD Waterbody, Permanent ID 44364468), public domain. State outline: U.S. Census Bureau TIGERweb. Points: Michigan DNR boating access sites and OpenStreetMap boat ramps (ODbL). Interactive map: Leaflet with © OpenStreetMap contributors. Not for navigation.
We found 49 campgrounds and RV parks within 15 miles of Thornton Lake, 10 of them within 5 miles. Distances are straight-line from the nearest point on the shoreline, so driving distance is longer.
RVs welcome · Dogs allowed
RVs welcome · Tent sites · Drinking water · Dogs allowed
RVs welcome · Tent sites · Drinking water · Dogs allowed
RVs welcome · Tent sites · Drinking water · Dogs allowed
Tent sites · Dogs allowed
All campgrounds & RV parks in Michigan
Green tent icons on the lake map mark campgrounds near the shore, and the interactive map shows the closest 12. Amenities are listed only where a source records them; call or check the campground's website before you go, since seasons and rates change every year.
Campground data: Recreation.gov (RIDB) · OpenStreetMap contributors (ODbL). Pulled Oct 12, 2026.
Live from the National Weather Service API for the lake's coordinates (46.2447, -86.6229). The nearest station may be several miles away. NWS forecast for Thornton Lake. No live water-temperature sensor is shown because we haven't found a public one for this lake.
Based on solunar theory, an estimate. Major periods (about 2 hours) center on when the moon is directly overhead or underfoot; minor periods (about 1 hour) center on moonrise and moonset. The 0–100 activity score rises during those periods and gets a boost near sunrise and sunset and around the new and full moon. Weather, water temperature and pressure often matter more. Sun and moon times are calculated in your browser from the lake's coordinates with standard astronomy formulas, shown in ET (America/Detroit), and accurate to within a few minutes.
1 public access site listed, 1 with a boat ramp or trailer launch.
| Site | Town | Owner | Type | Parking | Fee | Uses | Map |
|---|---|---|---|---|---|---|---|
| Boat ramp | Munising | — | Boat ramp (OpenStreetMap) · Yes ramp | — | — | Boating | 46.2444, -86.6194 |
Michigan DNR boating access sites and OpenStreetMap boat ramps (ODbL)
Fees, hours and rules change; confirm with the site owner before you go.
Thornton Lake covers about 30 acres in Munising, Michigan (Alger County).
The maximum recorded depth is 15 feet, according to the Michigan DNR stocking and lake depth records.
Yes. 1 public trailer launch is listed: Boat ramp. Check posted fees and parking rules.
Yes. We list 49 campgrounds and RV parks within 15 miles, 10 of them within 5 miles.
Thornton Lake touches Munising in Alger County, Michigan.
Know Thornton Lake? Tell us about the launch, parking, where they're biting or anything a first-time visitor should know. Tips go privately to the LakeRipple editor; nothing is posted automatically. Helpful tips may be featured on this page (we'll use your first name only if you give one).
Straight-line distance between lake centers. All Michigan lakes & ponds · All waters in Munising