High Quality Content by WIKIPEDIA articles! State Road 378 is a 3.4 mi (5.5 km) long state highway in far northern New Mexico. Beginning at a junction with New Mexico State Road 522, NM 378 heads generally west through the small town of Cerro and officially ends shortly thereafter at the boundary of BLM lands. The paved surface continues a few miles further under a different designation to end at the BLM`s Wild Rivers National Recreation Area.