They are the first range of mountains east of San Francisco Bay and stretch from the Carquinez Strait and San Pablo Bay in the north to Alameda Creek/Highway 84 in the south, crossing both Contra Costa and Alameda Counties.

[3] Although not formally recognized by United States Geological Survey (USGS) Geographic Names Information System, the East Bay Hills is included as part of the Diablo Range[4] in the USGS list of multiple GPS coordinates for the Diablo Range.

[18] The largest coast redwood tree was reported in 1893 by William P. Gibbons (1812-1897), the American naturalist, physician and founding member of the California Academy of Sciences, who measured the hollow shell of a coast redwood in the Oakland Hills with diameter of 9.9 metres (32 ft) at chest height.

[19] The East Bay Hills has lost more homes to wildfires than almost all of the high risk Southern California counties combined as of 2000.

[20] The East Bay Regional Park District is implementing vegetation treatments to reduce fire fuel loads on up to 2,280 acres (9.2 km2) in Contra Costa and Alameda Counties in the East Bay Hills.