Geologic Guide to Mount Diablo State Park A must have for all those interested in geology. July 1, 1998 The need for a simplified geological guide to Mount Diablo to accompany Memoir 217 was recognized by the Northern California Geological Society, Mount Diablo Interpretive Association, and California State Parks. A folded two-sided guide, edited by Greg Bartow, is now available, that consists of an updated geologic map with roads and trails on one side, and a description of the geology on the other side. The updated geologic map, by Russell Graymer and Victoria Langenheim of the U.S. Geological Survey, also appears in Chapter 1 of GSA Memoir 217. The guide includes a map showing the epicenters of 7,200 earthquakes that have occurred in the vicinity of Mount Diablo over the last 36 years. These earthquakes illustrate the active nature of the fault systems that continue to form Mount Diablo. Stephen Smith, President of Mount Diablo Interpretive Association, said, “This geologic guide will provide a new resource for visitors to appreciate the unique nature of the park.” Mount Diablo State Park draws more than 600,000 visitors each year to explore the park and take in the spectacular view. Mount Diablo Interpretive Association (MDIA) is a non-profit, all-volunteer organization that assists the California Department of Parks and Recreation in maintaining and interpreting Mount Diablo State Park. Through education, sponsored activities, and publications, MDIA fosters appreciation and the enlightened use of Mount Diablo State Park. Save Mount Diablo is a non-profit organization dedicated to the preservation of Mount Diablo peaks, surrounding foothills and watersheds through land acquisitions. Copies of the geologic map can be purchased online at the MDIA Store for $7.00 (shipping included), or for $6.00 at the Visitor Centers at Mount Diablo State Park Summit and Mitchell Canyon. Geology Map Cover.png Geology Map text side photo.JPG Geology Map map side photo.JPG BACK TO LIST

Mount Diablo Western Toad by Joyce Gross A Preliminary Survey April 1, 1998 By Chris Brown, US Geological Survey, Western Ecological Research Center - San Diego Field Station [Public domain], via Wikimedia Commons In April 1998 I photographed Bufo boreas (western toads) breeding and laying eggs in Little Pine Creek. Of the approximately 20 toads present, females predominated. My previous experience observing amphibian breeding congregations indicated that this was unusual--normally there are more males than females--but I didn't realize how unusual until Bruce Waldman, a herpetologist at the University of Canterbury, New Zealand, saw my photos. Bruce also pointed out that many of the eggs I had photographed were irregularly shaped and not viable, probably "old" eggs, ovulated a week or more prior to actual oviposition. Bruce and I monitored Little Pine Creek in the spring of 1999. Toads always return to the same locations to breed. However, we saw no evidence of reproductive behavior. We found no toads, no eggs, and no tadpoles. Amphibian population declines have been occurring with alarming frequency all over the world during the past few years. There are many possible causes, including pathogenic organisms (e.g. chytrid fungi), high UV-B radiation, exotic predators, and habitat destruction. One of the least understood possible causes is pollution by pesticides, herbicides, and residues of commercial plastics. These compounds are similar in chemical structure to estrogen and other reproductive hormones. Thus it is feared that even at very low concentrations, which may pose no toxicological risk to organisms, these chemicals may mimic female hormones and disrupt normal endocrinological processes. The result might be altered reproductive timing that could contribute to reproductive failure. Of course in this case the reasons for our observations may be completely unrelated to the causes about which we are speculating. In 2000, we received a permit from the park to study the toads and test a few if we found evidence of reproductive abnormalities. I visited the park twice a week from February through June. I found normal breeding activity, resulting in small toadlets by June, in two locations in the park: two miles away at the pond off the Bruce Lee trail in Mitchell Canyon, and two miles in the other direction in a cattle pond near China Wall. At Little Pine Creek there was once again no evidence of reproductive behavior. I found two juvenile toads, but no adult toads in or near the creek, and no eggs and no tadpoles. What happened to the adult toads in the vicinity of Little Pine Creek in Mt Diablo State Park remains a mystery. http://amphibiaweb.org BACK TO LIST

Wildflower Mount Diablo Woolly Fishhooks Scientific Name: Ancistrocarphus filagineus Family: Asteraceae (Sunflower Family) Blooms: Mar-May Color: Green Annual herb Native Jump to Blooming Now Blue / Purple Red / Pink White Yellow / Orange Invasive Plants

Wildflower Mount Diablo California Pitcher Sage (Purple) Scientific Name: Lepechinia calycina Family: Lamiaceae (Mint Family) Blooms: Apr - Jun Color: Blue-Purple Shrub Native, endemic to California Jump to Blooming Now Blue / Purple Red / Pink White Yellow / Orange Invasive Plants Mike Woodring

Wildflower Mount Diablo Colchita Scientific Name: Acmispon brachycarpus Family: Fabaceae (Legume Family) Blooms: Apr - May Color: Yellow-Orange Annual herb Native Jump to Blooming Now Blue / Purple Red / Pink White Yellow / Orange Invasive Plants

Wildflower Mount Diablo Scarlet Pimpernel Scientific Name: Lysimachia arvensis Family: Myrsinaceae (Primulaceae) Blooms: Mar - Jun Color: Yellow-Orange Annual herb Introduced Jump to Blooming Now Blue / Purple Red / Pink White Yellow / Orange Invasive Plants Mike Woodring

Wildflower Mount Diablo Goldfields Scientific Name: Lasthenia californica Family: Asteraceae (Sunflower Family) Blooms: Mar - Apr Color: Yellow-Orange Annual herb Native Jump to Blooming Now Blue / Purple Red / Pink White Yellow / Orange Invasive Plants Kevin Hintsa

California Digger Bee Anthophora californicus Apidae Anthophora Describe your image Describe your image Describe your image Describe your image Describe your image Describe your image Description Anthophora californica has ivory bands on the tips of each upper abdominal segment, which is otherwise black. These bands are not hair. Female bees also have prominent scopae on their hind legs, and green eyes. The males have prominent spines on their red hind tibiae. Nectar/ Pollen Plants Most local Anthophora are generalists. Habits California Digger Bees nest underground, but nesting details on Mount Diablo are not known. Season February - May; there may be a Fall generation too

Wildflower Mount Diablo Branched Lagophylla, Common Hareleaf Scientific Name: Lagophylla ramosissima Family: Asteraceae (Sunflower Family) Blooms: May Color: Yellow-Orange Annual herb Native Jump to Blooming Now Blue / Purple Red / Pink White Yellow / Orange Invasive Plants Steven Beatty Steven Beatty Leaf detail

Lotus Hairstreak Callophrys dumetorum dumetorum Lycaenidae Blues, Coppers, Hairstreaks Flies March to May Host Plant Buckwheat Nectar Plant Daniel Fitzgerald Underwing

Wildflower Mount Diablo Woodland Star Scientific Name: Lithophragma affine Family: Saxifragaceae (Saxifrage Family) Blooms: Mar - Apr Color: White Perennial herb Native V-shape sepal Jump to Blooming Now Blue / Purple Red / Pink White Yellow / Orange Invasive Plants Mike Woodring Stephen Smith, Steve Beatty Comparison of Woodland Star with Hill Star

Burrowing Owl Diurnal Birds of Prey Burrowing Owl Athene cunicularia All Year Diurnal Birds of Prey David Harper David Harper This small spotted owl lives in ground squirrel holes, feeding on insects, lizards, and small rodents. One of its warning cries sounds like the rattle of a rattlesnake.