Gratiot River
Michigan
Find: Amygdaloidal basalt & rhyolite, oolitic hematite jasper, epidote, garnets in gneiss, Lake Superior Agates
GPS: 47.34368, -88.45253
Nearest city: Houghton, MI
Recommended Vehicle: Any
Season: Accessible year round, Winter is likely to have significant snow, ice, and frigid temperatures.
Summary:
Pronounced like “Grash-it” River, this particular spot of coastline has some very unique geology. The rock here is almost like a water-worn washboard. Lake-tumbled stones are captured in the pockets of the smoothly worn bedrock. It makes for awesome photography and videography, especially underwater.
As for rockhounding, Gratiot River has plenty of fantastic finds to be made. The amygdaloidal basalt here is quite colorful, and the prehnite pieces I found were relatively large. Lake Superior Agates seem to be present, although few and far between. This beach usually has a good amount of people visiting in Summer months.
Video
Check out the video for a better look at what can be found when exploring this spot.
This is the 2nd spot listed in the video description links.
3 Helpful Tools
Chest Waders
Chest waders are great to stay dry if you want to get in the lake.
Agate Scoop
An agate scoop is helpful to pick things up faster and farther away from you.
Classifier
A classifier is fun to sit with if you’re a fan of small agates and stones. One with a larger, 1-inch mesh would be what I’d pick.
A look of what's meant by "washboard" under the water.
I think this is a little tube agate, but may be a coral.
Fairly confident this is some pink & green prehnite.
Amygdaloidal basalt. Lots of variety in color. A lot I've found in other areas of the lake have been spotted one with single color rather than this mix.
Epidote
Gotta be my favorite. I'm thinking rhyolite, but it may be something entirely different.