Name Sites Samples
Columbus County 1 5
Concho County 3 18
Concordia Parish 5 6
Conway County 3 16
Cooke County 5 19
Cooper County 3 12
Coryell County 116 362
Covington County 1 2
Cowley County 16 70
Crawford County 5 10
Crawford County 2 10
Crisp County 2 1
Crittenden County 1 6
Croatia 25 61
Crockett County 13 33
Cross County 6 26
Crow Wing County 7 19
Culpeper County 1 10
Cumberland County 3 12
Cumberland County 3 6
Cumberland County 1 1
Currituck County 3 7
Custer County 5 11
Cyprus 5 27
Czech Republic 123 420
Czechia 64 297
Dade County 1 3
Daggett County 58 206
Dakota County 2 3
Dallas County 1 1