1. Geological map of the Iowa Hill Mining District, Placer County / by J.B. Hobson, E.M., assistant in Creator: Hobson, J. B Published / Created: [1890?] Call Number: 844ca P69 1890 Container / Volume: BRBL_00613 Image Count: 3 Resource Type: Maps, Atlases & Globes Found in: Beinecke Rare Book and Manuscript Library > Geological map of the Iowa Hill Mining District, Placer County / by J.B. Hobson, E.M., assistant in the field.