Hand specimens of rocks collected as a part of field work conducted primarily by present and former WGNHS staff members. Samples date from the early 20th century to the 1990s and were collected throughout the state. Many of the samples are described in the historical field notebook collection, and relationships between the samples and the field notebooks have been established and captured in identifiers. Locations for samples were taken from field notes, maps, and accession lists. There are approximately 5,700 hand samples in this collection.