Rule: When two proper noun phrases are joined, if a word that is part of both phrases becomes plural and is not a proper noun, it’s not capitalized.
Hurricane Irma: School closures and event cancellations in Sarasota and Manatee counties
See the lowercase “counties”?
You could also say “Sarasota County and Manatee County,” but why would you?
BNI SWFL serves Charlotte, Collier, De Soto, Glades, Hardee, Hendry, Highlands, Monroe, Lee, Manatee, Polk and Sarasota Counties.
Now, you’d still write “Bowdoin College and Harvard University,” or “Temple Avenue and Collier Road,” but it’d be “the intersection of Darwin and Temple avenues.”