Yucca Mountain Project officials last week said they would try to address questions about design changes and the potential magnitude of the Bow Ridge fault, based on the new, preliminary ...

The fault ranks among the fastest moving in the Rocky Mountain region. Scientists think it could produce an earthquake as powerful as magnitude 7.5, which would cause serious damage.

Four fault zone maps were released along with 10 seismic hazard zones. One of the fault zones was in the Napa area where the 2014 earthquake occurred.

Click on a line for the name of the fault or on a dot for the magnitude and date of the quake. Information on the mapped quakes is from the U.S. Geological Survey earthquake catalog.

New earthquake restrictions on development are now in effect across a large swath of the northern San Gabriel Valley after the state released final maps for a section of the Sierra Madre fault zone.

The state’s new fault map would not halt Blvd6200’s construction, which is nearly complete, but the company wants the line removed. The developer of Rosedale, a large master-planned community ...

The Sierra Madre map also confirmed what officials knew about the fault line that runs through the base of the Sierra Madre Mountains and includes the communities of Sierra Madre, Azusa and Duarte.