Blackhawk Ranch Quarry

Blackhawk Ranch Quarry (HM1RHZ)

Location: Blackhawk, CA 94506 Contra Costa County
Buy California State flags at!
Country: United States of America
Buy United States of America flags at!

N 37° 50.972', W 121° 55.948'

  • 0 check ins
  • 0 favorites

A Paleontological Treasure

The Blackhawk Ranch fossil quarry is located south of Rock City on the lower slopes of Mount Diablo. During the Late Miocene, approximately 9-10 million years ago, this region was a rolling lowland. It represented the first evidence of emergence of the land around Mount Diablo after a long history of burial under the ocean.
Sycamore, elm, poplar and willow were common in the streamed forests, where animals such as Gomphotherium, a relative of the elephant, browsed among the trees, sharing the habitat with cranes, peccaries, and beavers.
Fossil evidence also indicates the presence of herbivorous animals including several kinds of horses, camels, rhinos, and pronghorns that probably favored open grasslands. There were also carnivorous sabre-toothed cats, a fox, and a very large hyena-like dog that may have preyed upon them.
Blackhawk Ranch Fossil Quarry

A picture of this ancient landscape and the plants and animals that lived there emerged through the excavation and analysis of the concentration of fossils from the Blackhawk Ranch Quarry.
Scientist from the University of California Museum of Paleontology have carefully studied the fossils from this quarry since its discovery in 1926, as well as the Late Miocene non-marine rocks in which these fossils were found. The geological and paleontological evidence left from the ancient ecosystem lies, hidden beneath the grassy slopes on the south side of the mountain.
Placed ByMt Diablo State Park
Marker ConditionNo reports yet
Date Added Wednesday, April 6th, 2016 at 1:01am PDT -07:00
Sorry, but we don't have a picture of this historical marker yet. If you have a picture, please share it with us. It's simple to do. 1) Become a member. 2) Adopt this historical marker listing. 3) Upload the picture.
Locationbig map
UTM (WGS84 Datum)10S E 593919 N 4189657
Decimal Degrees37.84953333, -121.93246667
Degrees and Decimal MinutesN 37° 50.972', W 121° 55.948'
Degrees, Minutes and Seconds37° 50' 58.32" N, 121° 55' 56.88" W
Driving DirectionsGoogle Maps
Area Code(s)925, 510
Which side of the road?Marker is on the right when traveling North
Closest Postal AddressAt or near Madrone Canyon Trail, Blackhawk CA 94506, US
Alternative Maps Google Maps, MapQuest, Bing Maps, Yahoo Maps, MSR Maps, OpenCycleMap, MyTopo Maps, OpenStreetMap

Is this marker missing? Are the coordinates wrong? Do you have additional information that you would like to share with us? If so, check in.

Check Ins  check in   |    all

Have you seen this marker? If so, check in and tell us about it.

Comments 0 comments

Maintenance Issues
  1. Is this marker part of a series?
  2. This markers needs some tags to help categorize the marker
  3. What historical period does the marker represent?
  4. What historical place does the marker represent?
  5. What type of marker is it?
  6. What class is the marker?
  7. What style is the marker?
  8. Does the marker have a number?
  9. What year was the marker erected?
  10. This marker needs at least one picture.
  11. Can this marker be seen from the road?
  12. Is the marker in the median?