To keep .zip file sizes below 1 GB, nonroad inventories were split by state:
part1: state FIPS 01-19
part2: state FIPS 20-29
part3: state FIPS 30-39 + 50-56
part4: state FIPS 40-49 + 72-78

Also, onroad_mex inventories were split by Mexican state:
part1: state FIPS 01-19, plus all othafdust, othar, onroad_can, othpt inventories
part2: state FIPS 20-32