The collection consists of letters, greeting cards, survey maps, newspaper clippings, legal papers, photographs, collected recipes, land sales and expense journals, and survey reference books. The material was created or collected by pioneering Nevada surveyor, engineer, and real estate entrepreneur J. T. (John Thomas) McWilliams and his wife, Iona, between 1900 and 1968.
Materials contain photographs from the Kiel (Taylor) Ranch from 1964, including photographs of the ranch, John Park's house, and other buildings. The Kiel Ranch was one of earliest non-indigenous settlements in the Las Vegas Valley, and it has become infamous as the site of the murders of Ed and William Kiel committed in 1900. The ranch is now in North Las Vegas and is administered by the North Las Vegas Neighborhood and Leisure Services Department.