For many years, bicycling on Mount Diablo has been a popular — but dangerous — activity. From 2010 to 2014, there were an average of 23 car and bike collisions per year.

ANTIOCH — Coal miners from a booming early Bay Area industry lay on their sides in 3-foot-tall tunnels to scrape and hack out soft black ore with pickaxes deep inside the Mount Diablo foothills ...

A bicyclist who was fatally hit by an SUV at a roundabout intersection in Lafayette was a “legend” in the local cycling community who once rode his bike up Mount Diablo every week for a decade.

Joe Shami, 83, of Lafayette, rides up to the summit of Mt. Diablo State Park in Contra Costa County, Calif., on Sunday, Jan. 14, 2018. Shami rode his 500th consecutive weekly bike ride up Mount ...

A bicyclist who was fatally hit by an SUV at a roundabout intersection in Lafayette was a “legend” in the local cycling community who once rode his bike up Mount Diablo every week for a decade ...

A 98-acre stretch in the Marsh Creek watershed containing “rare volcanic habitat” was acquired by Save Mount Diablo, a conservation organization, for wildlife preservation, the group announced ...

The view from Buckeye Hill at Shell Ridge, a view down the Briones-to-Mount Diablo Trail to the arrow spires of Castle Rocks -- with more geologic formations in the area -- and beyond to Mount ...

The quake struck at 12:49 a.m. and was located 2 kilometers northwest of the unincorporated community of Diablo, near Danville. It had a depth of 7.3 kilometers, according to USGS officials.