The U.S. Geological Survey conducted a 66-month-long study of earthquake activity near Albuquerque, New Mexico, during 1976-1981. Analysis of over 1000 hypocenters with magnitudes as large as 3.2 revealed that most of the seismicity fell into three regions: (1) the Socorro and Albuquerque areas of the Rio Grande rift, (2) the Mount Taylor area of the Jemez lineament, and (3) the Estancia basin. In the rift the hypocenters are shallow and largely confined to regions beneath the basins. Composite fault plane solutions suggest both normal and strike-slip faulting with an average T axis oriented WNW-ESE. Most of the young faults of the rift are seemingly inactive, and the rift as a whole cannot be delineated on the basis of seismicity.