Over the past several decades two federal agencies, the U.S.


Over the past several decades two federal agencies, the U.S. Navy and and the U.S. Army Corps of Engineers have shipped over 1,000 cubic feet of maps and drawings to our facility. These items came to our facility rolled, undescribed, and in poor containers. Over the past several years we have begun to flatten, described, and properly store these maps and drawings.

How do we do it? We pull a roll of tightly wound drawings from their original containers and check the condition of the items. The drawings are then placed in one of two humidification chambers. These chambers trap humidity, which allows a slight raise in the moisture content of the maps and drawings. The items are then removed from the humidification chambers and placed between wool felt, and spun polyester. A plexiglass cover and weights are placed on top. This allows the moisture to evaporate, keeps the items separated, and helps keep them flat. Once they are flat, they are put in large map folders, listed in our inventory database, and placed in a map cabinet in the temperature and humidity controlled archival storage area.

Some of these drawings document the development of flood control in southern California and Arizona. Some of them document military sites such as the old El Toro base in Orange County, California. All of them are unique and contribute to the history of our area.