Mo. Rev. Stat. § 128.345
All references in sections 128.345 to 128.366 to counties, voting districts (VTD), and tract-blocks mean those counties, voting districts (VTD), and tract-blocks as reported to the state by the United States Bureau of the Census for the 1990 census. All references in sections 128.400 to 128.440 to counties, voting districts (VTD), and tract-blocks (BLK) mean those counties, voting districts (VTD), and tract-blocks (BLK) as reported to the state by the United States Bureau of the Census for the 2000 census.
(L. 1991 S.B. 369 § 12, A.L. 2001 H.B. 1000)