Knife River beaches: Lake Superior Agate Rockhounding in Lake County, Minnesota
- Mineral reported
- 1
- Elevation
- 590 ft
- Best months
- April to October
The cobble beaches at Knife River are one of the North Shore's most reliable places to hunt Lake Superior agate, Minnesota's state gemstone, formed roughly a billion years ago in the gas vesicles of Keweenawan basalt along the Midcontinent Rift. Storms sort the shoreline gravel and expose fresh material, and both the lakeshore and the lower Knife River banks produce banded agate. The Knife River Marina beach offers rare, dedicated public parking and access directly on Lake Superior. Reported finds include lake superior agate. Below: coordinates, access notes, nearby spots, and trip-planning links.
Plan your visit
Generally open to casual rockhounding
- County
- Lake County
- State
- Minnesota
- Nearest road
- Sciff Landing Road
- Postcode
- 55609
- Coordinates
- 46.95035, -91.77834
Coordinates are approximate. Confirm the exact ground in the RockHoundR app, where land overlays show which agency manages the area.
Land & collecting status
Generally open to casual rockhounding
Most public-tagged spots sit on BLM, U.S. Forest Service, or other federal land where reasonable hand collecting of common rocks and minerals is allowed. Confirm posted rules and active mining claims before you dig.
Access note: Free public access at the Knife River Marina beach (public parking off America Dock Road) and the adjacent shoreline. Surface collecting of loose gravel only; no digging into banks. Managed as a DNR public water access rather than a state park, so casual agate collecting is allowed.
Public-land rules vary by agency, season, and field office. The RockHoundR app pulls live BLM, USFS, NPS, and tribal overlays so you can see exactly which agency manages the ground at this spot.
Best time to visit Knife River beaches
Comfortable months (45 to 90°F highs)
Best months: April to October. Typical highs run 75°F in midsummer and 24°F in midwinter, with winter lows near 8°F.
Climate normals: NOAA 1991-2020 monthlies, TWO HARBORS station (7 mi away).
Geology at Knife River beaches
This spot sits on Basalt and basaltic andesite, mapped as basalt and basaltic andesite that formed roughly 1200 to 1000 million years ago. Volcanic ground like this is where agate, jasper, and other chalcedony typically form, filling old gas pockets and fracture seams in the flow rock.
- Mapped unit
- Basalt and basaltic andesite
- Age
- 1200–1000 Ma (Mesoproterozoic)
- Rock types
- basalt and basaltic andesite
- Elevation
- 590 ft
Geologic mapping via Macrostrat and the underlying state geological survey maps (CC BY 4.0). Bedrock at the surface can vary within a mapped unit.
Today's weather
Is today a good day to go?
The app shows live weather, recent rain, and a daily rockhounding score for Knife River beaches.
Get the appSources & verification
Spot details combine the public RockHoundR location dataset, normalized mineral labels, agency land-status checks in the app, and community submissions. Coordinates are approximate until verified in the field.
- Minnesota Geological Survey
- Minnesota DNR state land rules
- Superior National Forest
- Community submissions reviewed against published agency rules
Found at Knife River beaches
Each name opens all spots that produce that material; the encyclopedia link opens the full ID and field guide.
Nearby rockhounding spots
Other rockhounding spots within driving distance of Knife River beaches.
- French RiverSaint Louis County, Minnesota · 7 mi awayLake Superior Agate
- Kelsey BeachLake County, Minnesota · 10 mi awayLake Superior Agate
- Gull RockLake County, Minnesota · 27 mi awayLake Superior Agate
- Beaver BayLake County, Minnesota · 31 mi awayLake Superior Agate, Thomsonite
- Cloquet (area 2)Carlton County, Minnesota · 36 mi awayLake Superior Agate, Garnet, Greenalite
- CarltonCarlton County, Minnesota · 36 mi awayLake Superior Agate, Garnet, Greenalite
- CloquetCarlton County, Minnesota · 37 mi awayLake Superior Agate, Garnet, Greenalite
- Little Marais RiverLake County, Minnesota · 45 mi awayThomsonite, Zeolite
Across the state line from Knife River beaches
Knife River beaches is close enough to the Minnesota border that the next-closest rockhounding spots are in a neighboring state. Worth knowing if you are already on the road.
- Reefer Creek Rest AreaBayfield County, Wisconsin · 18 mi awayGranite, Agate, Banded Iron Formation
- Wisconsin PointDouglas County, Wisconsin · 20 mi awayLake Superior Agate, Jasper, Copper
- Port Wing MarinaBayfield County, Wisconsin · 22 mi awayGranite, Agate, Banded Iron Formation
- Amnicon FallsDouglas County, Wisconsin · 24 mi awayLake Superior Agate
- HerbsterBayfield County, Wisconsin · 26 mi awayGranite, Agate, Banded Iron Formation
- AnniconDouglas County, Wisconsin · 31 mi awayCopper
Knife River beaches FAQ
Where is Knife River beaches?+
What rocks and minerals can you find at Knife River beaches?+
Is collecting allowed at Knife River beaches?+
What tools should I bring to Knife River beaches?+
When is the best time to visit Knife River beaches?+
How do I get to Knife River beaches?+
More rockhounding in Minnesota
See all 53 Minnesota spots →
Open Knife River beaches on the map
Use the RockHoundR app for live land overlays, weather, geology, directions, and saved finds.
