Census 2000 pl 94 171 techdoc
Washington WI Wisconsin WV West Virginia WY Wyoming SummaryLevel 2 SUMLEV 3 9 N ...Used Cheyenne B40 Cheyenne B41 Northern Cheyenne B42 Southern Cheyenne B43-B45
https://www.census.gov/content/dam/Census/programs-surveys/rdo/TechnicalDocumentation/Census2000_pl94-171_techdoc.pdf