County Boundary File, 1970 (DIMECO) (M149V1)

DIMECO is a county boundary file in DIME (Dual Independent Map Encoding) organization created by the Census Use Study for its computer graphics research. Each record represents a straight line segment: 1) separating two counties; or 2) bounding a county on the U.S. border, and contains unique node numbers for the end points of the segments, coordinates for each node, Standard Federal Region code, and FIPS State and county codes for both sides of the segment. DIMECO was created from the Bureau of Public Roads (now Federal Highway Administration) State and county data bank, because of its excellent coordinates. However, the BPR file was difficult to use, due to its complicated organization, and contained no adjacency information. The BPR file, and hense DIMECO, are based on 1960 counties, which differ slightly from 1970 counties. DIMECO presently lacks independent cities in Virginia and Menonomes County in Wisconsin. Also, Hawaii and Alaska are entirely missing. Updates to correct these deficiencies are only in the planning stage now.