US 421 improvements, NC 194 (Jefferson Avenue) to US 321 (Hardin Street) Boone, Watauga County, WBS element 35015.1.1, federal aid project no. NHF-421 (31), state project no. 8.1751601, TIP project U-4020 : environmental assessment / - Conforti, John. ([Project Development and Environmental Analysis Branch, NCDOT],, 2006)