SAN FRANCISCO (CBS SF) — A series of lightning-caused fires in several Bay Area counties have been grouped together by Cal Fire’s Santa Clara Unit into what is now known as the SCU Lightning Complex fires.

The group is comprised of approximately 20 different fires that were sparked by lightning on Sunday and have burned at least 25,000 acres across five separate counties: Alameda, Contra Costa, San Joaquin, Santa Clara, and Stanislaus.

As of noon Tuesday, there was zero containment on the fires, which are burning in steep, inaccessible terrain, Cal Fire reported.