Chris Izworski

Michigan Rockhounding Conditions

The best time to hunt a Great Lakes beach is right after a storm, once the waves have settled. This page reads the wind, waves and marine warnings at 15 Michigan agate, Petoskey stone and fossil spots and tells you which ones were just turned over, which are still too rough, and which have gone quiet.

By , Bay City, Michigan. Live conditions load when the page opens.

Best beach right now

Reading the lakes…

Beach by beach

Best first. The strip under each beach is the wind blowing onto it over the last three days and the next two: tall bars are waves being driven onto the gravel, and the line marks now.

Agate Beach, Grand Marais

Lake Superior, Eastern U.P.

Checking conditions

Live wind, wave and alert readings load here.

    Lake Superior agates, Jasper

    Public beach: follow posted rules. Local public beach. EGLE says to check for local rock collecting rules; the state 25 pound annual limit applies on public property.

    Getting there and what to look for

    Township public beach with boardwalk parking off the north end of Grand Marais. Burt Township lists it as a public rockhounding destination.

    The classic Lake Superior agate beach. Work the wet gravel band right at the waterline and the fresh windrows a storm leaves.

    Faces N (350°) across 233 km of open water.

    Burt Township: Agate Beach Beach area on Google Maps

    Muskallonge Lake State Park

    Lake Superior, Eastern U.P.

    Checking conditions

    Live wind, wave and alert readings load here.

      Lake Superior agates, Jasper, Yooperlites

      Collecting allowed: 25 lb per year. State-owned land. Michigan limits rock, mineral and fossil collecting to 25 pounds per person per year, total, for personal use. Follow posted park rules.

      Getting there and what to look for

      State park on County Road 407 between Grand Marais and Deer Park. Lake Superior beach across the road from the campground. Recreation Passport required.

      The shore from here east toward Whitefish Point is Yooperlite country. Hunt it after dark with a 365 nm UV light.

      Faces N (5°) across 137 km of open water.

      Michigan DNR: Muskallonge Lake Beach area on Google Maps

      Crisp Point Lighthouse beach

      Lake Superior, Eastern U.P.

      Checking conditions

      Live wind, wave and alert readings load here.

        Lake Superior agates, Jasper, Yooperlites

        Public beach: follow posted rules. Local public beach. EGLE says to check for local rock collecting rules; the state 25 pound annual limit applies on public property.

        Getting there and what to look for

        Remote: a long drive on sand and gravel county roads north of M-123. Check road conditions before you go and expect no services.

        Long, lightly hunted open shoreline. Remote enough that conditions after a blow can stay good for days.

        Faces NNW (342°) across 111 km of open water.

        Crisp Point Light Historical Society Beach area on Google Maps

        F.J. McLain State Park

        Lake Superior, Keweenaw

        Checking conditions

        Live wind, wave and alert readings load here.

          Lake Superior agates, Jasper

          Collecting allowed: 25 lb per year. State-owned land. Michigan limits rock, mineral and fossil collecting to 25 pounds per person per year, total, for personal use. Follow posted park rules.

          Getting there and what to look for

          State park on M-203 north of Hancock. DNR notes rockhounding along its sandy and rocky Lake Superior shoreline. Recreation Passport required.

          Keweenaw gravel mixes agates with basalt and other volcanic beach stones. Look for the waxy, translucent ones.

          Faces NNW (335°) across 75 km of open water.

          Michigan DNR: F.J. McLain Beach area on Google Maps

          Presque Isle Park, Marquette

          Lake Superior, Central U.P.

          Checking conditions

          Live wind, wave and alert readings load here.

            Lake Superior agates, Jasper

            Public beach: follow posted rules. Local public beach. EGLE says to check for local rock collecting rules; the state 25 pound annual limit applies on public property.

            Getting there and what to look for

            City park at the north end of Lakeshore Boulevard in Marquette. Follow posted park rules and stay off the high rock edges in rough water.

            Faces east and northeast, so it gets worked by northeast blows that leave west-facing beaches calm.

            Faces ENE (58°) across 211 km of open water.

            City of Marquette Beach area on Google Maps

            Black River Harbor

            Lake Superior, Western U.P.

            Checking conditions

            Live wind, wave and alert readings load here.

              Lake Superior agates, Jasper

              National forest: small amounts. National forest land. Small amounts for personal use with hand tools; follow posted Forest Service rules.

              Getting there and what to look for

              U.S. Forest Service recreation area at the end of the Black River Scenic Byway (CR 513) north of Bessemer.

              A western U.P. option that turns over in north and northwest storms.

              Faces NNW (335°) across 117 km of open water.

              Ottawa National Forest Beach area on Google Maps

              Miners Beach, Pictured Rocks

              Lake Superior, Central U.P.

              Checking conditions

              Live wind, wave and alert readings load here.

                Lake Superior agates, Jasper

                No collecting: look only. National Park Service land. Removing rocks, minerals or fossils is prohibited under federal law. Look, photograph and leave them.

                Getting there and what to look for

                Pictured Rocks National Lakeshore, off Miners Castle Road east of Munising.

                Beautiful beach stones, but this is a national lakeshore: look, photograph and leave them.

                Faces NW (312°) across 141 km of open water.

                NPS: rock and fossil collecting Beach area on Google Maps

                Petoskey State Park

                Lake Michigan, Little Traverse Bay

                Checking conditions

                Live wind, wave and alert readings load here.

                  Petoskey stones, Devonian fossils

                  Collecting allowed: 25 lb per year. State-owned land. Michigan limits rock, mineral and fossil collecting to 25 pounds per person per year, total, for personal use. Follow posted park rules.

                  Getting there and what to look for

                  State park at 2475 M-119 north of Petoskey, with a day-use beach on Little Traverse Bay. DNR describes Petoskey stone hunting here. Recreation Passport required.

                  Petoskey stones show their pattern best wet. Hunt the swash zone, or carry a spray bottle.

                  Faces W (272°) across 71 km of open water.

                  Michigan DNR: Petoskey State Park Beach area on Google Maps

                  Fisherman's Island State Park

                  Lake Michigan, Charlevoix

                  Checking conditions

                  Live wind, wave and alert readings load here.

                    Petoskey stones, Charlevoix stones, Devonian fossils

                    Collecting allowed: 25 lb per year. State-owned land. Michigan limits rock, mineral and fossil collecting to 25 pounds per person per year, total, for personal use. Follow posted park rules.

                    Getting there and what to look for

                    State park on Bell's Bay Road south of Charlevoix with miles of undeveloped shoreline. DNR has reported day-use areas closed to vehicles during culvert repairs, with the shore still reachable on foot. Check the park page for current access.

                    Long, rocky stretches. DNR names rockhounding here; Petoskey and Charlevoix stones both turn up.

                    Faces NW (308°) across 97 km of open water.

                    Michigan DNR: Fisherman's Island Beach area on Google Maps

                    Van's Beach, Leland

                    Lake Michigan, Leelanau

                    Checking conditions

                    Live wind, wave and alert readings load here.

                      Leland Blue, Petoskey stones

                      Public beach: follow posted rules. Local public beach. EGLE says to check for local rock collecting rules; the state 25 pound annual limit applies on public property.

                      Getting there and what to look for

                      Public beach just north of the Leland harbor and Fishtown. Follow posted township rules.

                      Leland Blue is slag glass from the 1800s iron smelter. Van's Beach and North Beach are the usual starting points.

                      Faces WNW (290°) across 17 km of open water.

                      MyNorth: where to find Leland Blues Beach area on Google Maps

                      Glen Haven, Sleeping Bear Dunes

                      Lake Michigan, Leelanau

                      Checking conditions

                      Live wind, wave and alert readings load here.

                        Petoskey stones

                        No collecting: look only. National Park Service land. Removing rocks, minerals or fossils is prohibited under federal law. Look, photograph and leave them.

                        Getting there and what to look for

                        Sleeping Bear Dunes National Lakeshore, on Sleeping Bear Bay at the historic Glen Haven village.

                        Petoskey stones are common here, and the Park Service says it is illegal under federal law to remove stones from the National Lakeshore.

                        Faces N (2°) across 17 km of open water.

                        NPS: Sleeping Bear beaches Beach area on Google Maps

                        Frankfort Public Beach

                        Lake Michigan, Benzie

                        Checking conditions

                        Live wind, wave and alert readings load here.

                          Petoskey stones, Devonian fossils

                          Public beach: follow posted rules. Local public beach. EGLE says to check for local rock collecting rules; the state 25 pound annual limit applies on public property.

                          Getting there and what to look for

                          City beach at the west end of Main Street by the north breakwater. Follow posted city rules.

                          EGLE names the Frankfort public beach as a known Petoskey stone and fossil locality.

                          Faces WSW (250°) across 109 km of open water.

                          EGLE: Michigan fossils (names Frankfort) Beach area on Google Maps

                          Wilderness State Park

                          Lake Michigan, Straits

                          Checking conditions

                          Live wind, wave and alert readings load here.

                            Petoskey stones, Devonian fossils

                            Collecting allowed: 25 lb per year. State-owned land. Michigan limits rock, mineral and fossil collecting to 25 pounds per person per year, total, for personal use. Follow posted park rules.

                            Getting there and what to look for

                            State park west of Mackinaw City with 26 miles of Lake Michigan shoreline. Recreation Passport required.

                            So much shoreline that you can usually find a stretch nobody has walked since the last blow.

                            Faces N (7°) across 17 km of open water.

                            Michigan DNR: Wilderness State Park Beach area on Google Maps

                            P.H. Hoeft State Park

                            Lake Huron, Northeast Lower

                            Checking conditions

                            Live wind, wave and alert readings load here.

                              Devonian fossils

                              Collecting allowed: 25 lb per year. State-owned land. Michigan limits rock, mineral and fossil collecting to 25 pounds per person per year, total, for personal use. Follow posted park rules.

                              Getting there and what to look for

                              State park on US-23 just north of Rogers City, with a mile of Lake Huron beach. Recreation Passport required.

                              This is Devonian limestone country. Look for brachiopods, crinoid stems and coral fragments in the beach cobble.

                              Faces NE (37°) across 59 km of open water.

                              Michigan DNR: P.H. Hoeft Beach area on Google Maps

                              Rockport State Recreation Area

                              Lake Huron, Northeast Lower

                              Checking conditions

                              Live wind, wave and alert readings load here.

                                Devonian fossils

                                Collecting allowed: 25 lb per year. State-owned land. Michigan limits rock, mineral and fossil collecting to 25 pounds per person per year, total, for personal use. Follow posted park rules.

                                Getting there and what to look for

                                Former limestone quarry north of Alpena off US-23. DNR lists searching for fossils among its activities. Recreation Passport required.

                                Quarry hunting is not wave-dependent. Any dry day works, and the loose limestone is full of Devonian brachiopods and corals.

                                Inland quarry: waves do not matter here.

                                Michigan DNR: Rockport Beach area on Google Maps

                                How the reading works

                                Michigan's geologists at EGLE give one rule for timing a hunt: go immediately after a storm, because new material is washed up, and do not go during the storm or when there is high wave action. Everything here is that rule, measured.

                                1. Which way the beach faces. For each beach we computed the direction of open water in front of it and how far that water runs, from the mapped lake shoreline. A north wind that slams Grand Marais barely touches Presque Isle in Marquette, which faces northeast.
                                2. How hard waves were driven onto it. Every hour of the last three days, we take the part of the wind blowing from the lake straight onto the beach, scale it by the open water it crossed, and count only the hours strong enough to move gravel. Wind is used because it is measured everywhere, all year; wave buoys are pulled out of the lakes every fall.
                                3. Whether it has settled. If the wind is blowing onto the beach right now it reads Waves building: wait. If that onshore wind is strong, or the National Weather Service has a gale, storm, beach hazards or lakeshore flood alert for the beach or its nearshore water, the beach reads Storm on: stay off. When a real blow has passed, it reads Freshly worked: go. The nearest NOAA wave buoy is shown when one is reporting.

                                This tells you where the lake has recently done the digging. It cannot tell you what any one beach is holding today, and the National Weather Service is the authority on safety: if waves are breaking hard, stay well back from the water and off breakwalls and wet rock.

                                What you are looking for

                                Lake Superior agate

                                Banded quartz that formed in gas pockets of lava flows from the Midcontinent Rift about 1.1 billion years ago, then was spread south by glaciers. Look for a waxy shine, iron reds and oranges, and stone that glows when you hold it up to the sun. Fine concentric bands are the giveaway; the outside is often pitted.

                                Jasper

                                The opaque cousin of agate: dense, smooth, brick red to brown and no light passes through it. Common on the same Lake Superior beaches, and often the first red stone that catches your eye.

                                Yooperlite

                                Plain gray syenite by day, glowing orange-yellow under a longwave 365 nm UV light at night because of the fluorescent mineral sodalite. Named in 2017 by Erik Rintamaki; most finds come from the eastern U.P. shore toward Whitefish Point. Wear UV-blocking glasses.

                                Petoskey stone

                                Michigan's state stone: Hexagonaria percarinata, a colonial coral from Devonian seas about 350 million years ago. Each six-sided cell has a dark center, and the pattern only shows when the stone is wet or polished, so hunt the swash zone or carry a spray bottle.

                                Charlevoix stone

                                Another Devonian coral, Favosites, often called honeycomb coral. The cells are smaller than a Petoskey's and lack the dark eye in the middle. Found on the same northern Lake Michigan beaches.

                                Leland Blue

                                Not a natural stone: blue and blue-green slag glass left by the iron smelter that ran at Leland in the 1870s and 1880s. Bubbles and a glassy shine give it away. Look along the Leland shoreline.

                                Devonian fossils

                                The limestone of northeast Lower Michigan is packed with sea life: ribbed brachiopod shells, crinoid stems that look like stacks of tiny washers, horn corals and lacy bryozoans. EGLE suggests looking right after a big wave event, when fresh fossils erode out.

                                What you can take home

                                Sources: EGLE rockhounding guidance, EGLE Michigan fossils, National Park Service collecting rules. This is a plain summary, not legal advice.

                                Questions

                                When is the best time to look for agates in Michigan?

                                Right after a storm on Lake Superior, once the wind has dropped and the waves have settled. Storm waves churn the beach gravel and bring fresh stones to the surface, and EGLE's guidance is to go immediately after a storm but never during one. Spring, just after the ice goes out, and fall, when storms are frequent and beaches are quiet, are the strongest seasons.

                                Where can I find Lake Superior agates in Michigan?

                                On Lake Superior gravel beaches across the Upper Peninsula. Agate Beach in Grand Marais, the shore from Muskallonge Lake State Park east toward Crisp Point, F.J. McLain State Park in the Keweenaw and Black River Harbor in the western U.P. are all public options on this page. Pictured Rocks beaches have agates too, but collecting there is prohibited.

                                Where is the best place to find Petoskey stones?

                                Northern Lake Michigan from Little Traverse Bay to Charlevoix and down the Leelanau and Benzie shore. Petoskey State Park, Fisherman's Island State Park, Wilderness State Park and the Frankfort public beach are public places to hunt. Sleeping Bear Dunes has them too, but it is illegal to remove stones from the National Lakeshore.

                                How many rocks can I take from a Michigan beach?

                                On state-owned land, including state parks and the public Great Lakes shoreline, EGLE limits collecting to 25 pounds of rocks, minerals and fossils per person per year in total, for personal use. Local parks can have their own rules, national lakeshores prohibit collecting entirely, and private land needs the owner's permission.

                                Is it legal to take rocks from Pictured Rocks or Sleeping Bear Dunes?

                                No. Both are National Park Service lakeshores, and federal rules prohibit removing rocks, minerals or fossils. Enjoy them where they lie and take photos instead.

                                How does this tool decide a beach was freshly worked?

                                It adds up the wind that blew straight onto each beach over the last three days, scaled by how much open water lies in front of it, and checks that the wind has since eased and no gale, storm, beach hazards or lakeshore flood alert is in effect. Strong onshore wind recently, calm now, reads as freshly worked. It measures the lake's work on the beach, not what any one beach is holding.