in the 1920s, marvin greathouse started mining sand here for use in glassmaking, so anything from a heinzo salt and pepper shakers. the sand here is a high-quality silica sand that is not found in common beach sand in the bay area. we can look up into some of these rooms called stopes that are these huge, large areas that they would have dynamited the sand out of to bring it out for glassmaking. you're not only learning about the history of sand mining in this era, but also getting to experience what it might have been like to be in a mine during sand mining here. caldwell: one of the exciting things about this place is we're always learning more and unearthing more history and sharing that with the public. i think that's a really exciting thing that we get to do here. that's it for today's show, but tune in next week for an all new episode. in the meantime, keep connected on social for more feel-good stories. hey, bay area. it's time to share some amazing stories and feel good. we could all use some inspiration right now, and you've come to the right place. this show is all about good fo