There was a third earthquake this morning, a magnitude 2.2 event possibly under Lake Mead. The USGS lists it as occurring in Nevada but their most detailed map shows it just over the border in Arizona. [right, location map from USGS]
Earlier today, we had magnitude 2.4 and 2.o events nearby.
update 7-27-11 4pm: all 3 quakes are now gone from the USGS earthquake page and list. We assume they decided they were not tectonic, ie, they are due to the lake filling??, and so deleted them.