Minnesota

Webshots, great photos of Mystery Cave and Niagara Cave and their history on Cave Country  Photo . net Niagara Cave

Department of Natural Resources Forestville/Mystery Cave  Wikipedia page

Finding Minnesota I couldn't make the video go but it looks like there is no lighting inside Mystery Cave. This page has text with history but no other photos. 

Niagara Cave in Harmony, Minnesota. This page has some thrilling photos. Take the About our Tour link to find another awesome photo (am I looking down or ahead) with some history and description. And check out the gemstone mining.

The Wild & Scenic Cannon River, Minnesota River, Rum River, Kettle River and Mississippi River and the St. Croix National Scenic Riverway  Cannon River, The Wikipedia page and their page for Miesville Ravine Park Reserve.

Chippewa Falls, Chippewa River

Superior Trails . com has a fine collection of waterfalls Waterfalls page by MichelesWorld,

Gooseberry Falls Arch in Gooseberry State Park