High Quality Content by WIKIPEDIA articles! New Mexico State Road 4 is a state highway in New Mexico, United States of America. It is significant as the main access route (in conjunction with New Mexico State Road 501 and New Mexico State Road 502) connecting the remote town of Los Alamos, Los Alamos National Laboratory, and Bandelier National Monument to other, more major highways in New Mexico. Its total length is approximately 64 miles (103 km).