There seems to be an open section of Hwy 10 just north of St. Cloud. I have not contacted the DOT to verify availability. It's a mile long, presumably because it's close to a city and gathers more litter. It has blank signs up starting a mile north of the 10/15 split.
Does anyone think we could assemble enough humanpower to tackle this twice a year? Minnesota Atheists already does the two-mile section immediately north of Rice, so there's some overlap in interest, I'm sure.