Butte, America’s Story Episode 263 - Sanborn Maps

Welcome to Butte, America’s Story. I’m your host, Dick Gibson.

Sanborn Fire Insurance Maps provide some of the best resources for understanding the neighborhood context and history of old buildings in Butte.

The Sanborn Company began making the detailed maps in 1867, beginning in the Eastern United States. They were used as the gospel by insurance agents to determine liability – and cost of premiums – based on building materials, neighboring buildings, and proximity to fire stations and gas and water mains.

In Butte, Sanborn Maps help us discover the history of vacant lots at the northern corners of Copper and Alaska Streets – where two churches once stood. On the northwest corner, the Swedish Methodist Episcopal Church occupied the second floor of a small brick-veneered wood frame building, with housekeeping rooms on the first floor. In 1916, the building had heat stoves and electric lights. The double hydrant mapped by Sanborn at the corner of this building probably reduced its insurance rate, although its wood shingle roof may have counted against it.

Across the street, the two-story Gold Hill United Lutheran Church included a domicile in the basement, probably for the pastor. It too was electrified in 1916, but it was heated by stoves, and it had masonry bearing walls. All that information comes from the Sanborn maps.

The maps reveal interesting details that an insurer or fire department (or historian) might need. The Original Mine, for example, in 1916 was “run day & night – three 8 hour shifts – day & night watchman. Power was from compressed air & electric; heat was steam; fuel was coal; and city water was from hydrants & hose as shown.” The maps even indicate that chemical fire extinguishers were distributed around the mineyard.

In Butte in 1916, it took 115 sheets nearly two feet square, at a scale of 1 inch to 50 feet, to cover the city.

Individual buildings were surveyed by Sanborn’s army of agents, so sizes and details as portrayed on the maps right down to the positions of fire escapes and heights of parapets are generally remarkably accurate. For Butte, we have maps from 1884, 1888, 1890, 1891, 1900, 1916, 1951, and 1957, which leaves tantalizing and sometimes frustrating gaps for us to try to fill in from other sources.

But for historical research, both for existing structures and vacant lots, the Sanborn Maps online or those housed at the Butte-Silver Bow Public Archives are excellent resources.

As writer Edwin Dobb has said, "Like Concord, Gettysburg, and Wounded Knee, Butte is one of the places America came from." Join us next time for more of Butte, America’s Story.