Historical Research, Historical Forensics, and Toxic Torts

Historical Research

A/HC creates detailed portraits of people and places in Bay Area and California history. Our expertise includes land use history, historical ethnography, corporate histories, and the history of industrial processes and facilities.

Our historical research services include:

  • Interpretive Panels and Brochures
  • National Register Nominations
  • Historical profiles of individual properties and local neighborhoods
  • Corporate and Organizational History
  • Oral History and Qualitative Research

sample projects

A/HC has produced several important books on the ethnohistory of the Ohlone and Coast Miwok peoples, with archaeologist Randall Milliken.

Book Cover of Inigo

Yñigo of Rancho Posolmi tells the story of Lope Yñigo, an Ohlone man born before the Spanish arrival in California. Yñigo survived the Mission system and was one of the few Native Americans to receive a land grant under Mexican rule, which he retained until his death in 1864.

Ohlone/Costanoan Indians of the San Francisco Peninsula and their Neighbors, Yesterday and Today and Ethnohistory and Ethnogeography of the Coast Miwok and their Neighbors, 1783-1840 are studies of the Ohlone and Miwok peoples for the National Park Service. They provide stories of Native peoples’ resistance and survival under the Mission system and into the 20th century.

Toxic Torts and Historical Forensics

A/HC helps clients manage environmental liabilities through forensic historical research that identifies historical sources of soil and groundwater pollution and Potentially Responsible Parties (PRPs). Since 1985 we have prepared histories for hundreds of industrial and commercial brownfield sites throughout California. We are experts in the historical uses of a wide range of potentially toxic substances, including petroleum products, heavy metals, pesticides, and PCBs. Our expertise also includes corporate history and corporate successorship research, which clients have successfully used to identify PRPs.


  • Dry cleaners
  • Manufactured gas plants
  • Power stations
  • Foundries
  • Tanneries
  • Pipelines
  • USTs


  • Coal tar, lampblack, creosote, solvents, PAHs
  • Lead, mercury, chromium, arsenic
  • Asbestos, pesticides, and PCBs

Project Highlights

North Beach Land Use Study, San Francisco

For this project, A/HC completed a forensic historical analysis of a 20-block area in the North Beach district of San Francisco, including reconstruction of historic shorelines, identification of historic industrial uses, and detailed histories of potential sources of soil pollution.

Butchertown Land Use Study, San Francisco

In 2013, A/HC completed a historic land use study of San Francisco’s Butchertown, a former meat processing and tannery area along Islais Creek. We focused on identifying pollution from chromium and other toxic materials in order to identify potential PRPs.