I had been meaning to explore the white cliffs that are just to the north of Highway 101 and St. Croix – I found the time to poke about so I did.
At first, I thought this was the St. Croix River and that the cliffs were exposed gypsum. Nope – this is actually Thumb Hill Creek and the cliffs are exposed limestone. My mistake was due to the highway crossing a river, with a place name of St.Croix River, and then assuming that this section was part of the St.Croix.
Google is my friend when I research such things, both for maps and links to information about what I am looking at. The satellite view of the area cleared up the name of this section of river.
The limestone cliffs
Thumb Hill Creek flowing under Rock Road
Looking to the west toward the St. Croix River