The Los Alamos Scientific Laboratory is located in north-central New Mexico within an area of geologically recent volcanic and tectonic activity. A network of twelve short period seismic stations within 150 kilometers of Los Alamos is telemetered to LASL, and recordings are mailed from a similar station at Lukachukai, Arizona. These stations record most regional earthquakes having magnitudes (M/sub L/) greater than one. The seismic data thus obtained are used to study the contemporary tectonic activity near the Valles Caldera and the Rio Grande Rift between 35/sup 0/ and 37/sup 0/ north latitude. The regional epicenter map for the period September 1973 through December 1975 shows earthquake concentrations (1) along the Nacimiento Uplift and its northward extension to Dulce, NM, (2) near Abiquiu, north of Los Alamos; (3) beneath the western part of the Taos Plateau; and (4) within the Rio Puerco fault zone, between Albuquerque and Grants. Almost no earthquakes are originating beneath the Valles Caldera, suggesting the presence of a hot shallow body where strain relief occurs by creep rather than by brittle fracture. The instrumental and historical seismicity and earthquake evidence from fault displacements consistently show the overall region to have moderate activity.