There's not a lot to see driving on I-90 through Minnesota. Our first stop was the Spam Museum in Austin (we first had a picnic lunch in a nice city park there). Austin is home of the Hormel company (locals pronounce it "hormull" and, yes, they actually have a small museum dedicated to Spam).
I would never have stopped there but my wife insisted (she likes kitschy stuff) and I have to say it wasn't bad. I'm not a big fan of Spam but the Hormel company put together a nice little museum to promote their product and even incorporated some humor into it (they had a video running of Monty Python's Spam routine, for example). It was free, too (although we did get my daughter a Spam tee-shirt).
When we pulled off the Interstate to get gas at Blue Earth, MN (named for the blue clay found along the river), we were surprised by a 55 foot tall statue of the Jolly Green Giant. Exciting, isn't it? There's also a museum but we passed on that. Some more trivia, Blue Earth is the exact middle of Interstate 90.
Eventually, we made it to the western part of Minnesota where we spent the night camping at Blue Mounds State Park (named because weathered outcrops of Sioux Quartzite appeared blue to the early settlers). Up close it's pinkish to purplish.
The Sioux Quartzite is interesting for a number of reasons. It's found in western Minnesota and eastern South Dakota and is around 1.7 billion years old (it can't be directly dated but its age can be constrained by upper and lower units and by correlation with similar-age units). It's a metamorphosed very pure quartz sandstone (parts are conglomeritic) which apparently formed in a braided river channel to shallow marine environment (it formed at the edge of the continent back then). Cross-bedding and ripple marks are common but it doesn't have fossils.
It's a very hard rock colored various shades of pinks, reds, and purples due to small amounts of oxidized iron and makes an attractive building stone. Here's an old quarry at Blue Mounds (the entire foreground of the image was quarried out).
Here's a closeup of the block straight in front of the path in the picture above. It really is an attractive rock.
Another interesting thing about the park is a 1,250 foot line of rocks which have an east-west alignment. They can be used to show the direction of the rising and setting Sun on the vernal and autumnal equinoxes. Archaeastronomy alignment? Native American built? No one really knows who built it or when it was constructed. Hard to show in a picture though since they have let prairie grass grow up around the rocks.
The park also has a fenced bison herd, but we didn't see it. It was a nice place to camp.
Sunday on to South Dakota and the Badlands.