 As an Interstate highway, by default, I-70 is a part of the National Highway System, a network of highways deemed most important for the country's economy, mobility and defense.The portion of I-70 between I-675 and Enon Road in Clark County is designated as the "Deputy Suzanne Hopper Memorial Highway", in honor of a Clark County Sheriff's deputy who was shot and killed on January 1, 2011 while responding to reports of gunshots at a mobile home park on Enon Road, near I-70.I-70 appeared on the original AASHTO interstate route numbering map from August 14, 1957.