4th Grade Field Trip to Black Diamond Mines

Did you grow up in the San Francisco Bay Area? I did, and I had never heard of the Black Diamond Mines in Antioch, California until the Village 4th graders went on a field trip there. The Black Diamond Mines Regional Preserve is a 6,000-acre park located north of Mount Diablo in Contra Costa County, under the administration of the East Bay Regional Park District. The park is a former coal and sand mining site with expansive green space, tours of the mines and hiking trails that go by a small pond and an old cemetery. One of the Park Rangers described it as “The East Bay’s best kept secret,” and I have to agree – it’s beautiful.

Our field trip started off with the kids hiking up a large hill to where the mines are located. They were greeted by the Park Rangers who provided a little history of the area and went over safety rules. The kids put on their hard hats and headed off into the Somerville mine, which supplied the sand used in glass marking by the Hazel-Atlas Glass Company in Oakland.

The first part of the tour was spent going over safety and how important it was for the miners. The miners flipped over silver tags to indicate they were working in the mine that day. That way, if there was an accident, the site Supervisor knew who and how many were stuck in the mine. The Ranger pointed out a “safe” place the miners could hide in case there was an accident preventing them from escaping. The Ranger showed the kids the tools the miners used to mine the sand. He pointed out the railroad tracks and carts that moved the sand out of the mine, the picks and axes used to break down the sand and, most importantly, a replica of dynamite used to blow up sections of the mine to get to the sand. He also showed the kids sections of the mine that were blown away leaving large cavern-type areas.

One of coolest things the Park Ranger pointed out is tiny fossils lining the mine wall. The fossils are tiny sea creatures, bugs and even fossilized rain drops. The Park Ranger explained the park was under the sea thousands of years ago and that is why you see the fossils. He also said the rain runoff from the mountains filled the sea with minerals which were broken down and compressed to create the sand.

The kids finished up their field trip by hiking to the old cemetery sitting on top of the hill. The kids were very interested in reading the dates on the tombstones to see how long ago the folks passed away. They were surprised to see tombstones for young kids and babies. After that, the kids hiked backed down to the picnic benches to have their lunch and then back in the car to do the 1 ½ hour drive back to school.