Map/brochure: Park brochure/map provided with park entrance fee at visitor center; detailed trail map, $7.50, free with memberships, from Mount Diablo Interpretive Association, www.mdia.org.

The Diablo Summit has received 18.14 inches of rain this season, most of it in December. In comparison, for all of the previous year, Diablo recorded 6.56 inches.

It’s not (normally) found on Mount Diablo, so it had to have been traded by Indians … 100-plus years ago.” The arrowhead was documented and returned to where it was found.

Save Mount Diablo will expand its free Discover Diablo Hikes and Outings Program in 2025, including into areas rarely open to the public. The nonprofit conservation group’s program offers guided ...