The Rio Grande Rift project continues to be the main focus of the PBO EarthScope Campaign support group, with four more monuments installed in early December. The network will consist of 25 semi-permanent GPS stations in Colorado and New Mexico, 21 of which have now been completed. Project PI's Anne Sheehan and Steve Nerem of the University of Colorado, Tony Lowry of Utah State University, and Mousumi Roy of the University of New Mexico will analyze data acquired by these stations over the next five years to determine velocity and tectonic style associated with the Rift.

UNAVCO Facility staff designed special enclosures and systems to provide support for semi-permanent installations such as at station RG09 (figure 1), which consists of a shallow drilled-braced antenna monument (SDBM) and was completed on October 3, 2006, near Lindrith, New Mexico. The systems are comparable to those of permanent PBO stations but portable to allow removal and reuse by future EarthScope projects. The Rio Grande Rift project plan calls for station siting, reconnaissance, and permitting to be done by the PI institutions with SDBM installations to be done by UNAVCO Facility staff.

Locations identified by the Universities of Colorado and New Mexico were not always suitable for full SDBM installations due to access. Hence single-mast type monuments (figure 2), which require less hardware and equipment, were substituted at 8 of the 21 built locations.

To date data have been manually downloaded from 9 of the operational stations while one has permanent telemetry installed. Data quality have been excellent. Network status is shown in Figure 3.