Archives West Finding Aid

This collection contains aerial photographs and corresponding index sheets of locations in Central and Eastern Montana produced by the United States Department of Agriculture, as well as other governmental agencies and private companies during the years 1937 through 1968. Also included are undated controlled and uncontrolled aerial mosaics, many of which have transparent overlays depicting geological and historical information. Finally, the collection includes a set of geologic plane table sheets mapping locations in Central Montana created from 1920 to 1961.

Series I, Aerial Photographs and Index Sheets, includes reference maps and flight indexes to the aerial photographs in this collection, as well as index sheets and aerial photographs of locations in Montana. This series is divided into three sub-series.

Sub-series 1, Reference Maps and Flight Indexes, contains reference maps illustrating the geographic location of each set of index sheets and aerial photographs. A second index in this sub-series appears to contain information on individual flight passes for many of the aerial photographs held in this collection.

Sub-series 2, Aerial Photograph Index Sheets, contains oversized index sheets to be used in conjunction with corresponding aerial photographs in Sub-series 3. Prior to their arrival at the University of Montana-Missoula, index sheets in this collection were arranged numerically by assigned serial numbers. This original order has been maintained. In addition, they are typically grouped together and placed in labeled folders when they were produced at the same time by the same agency, and cover the same geographical area. For example, index sheets 60042-60047, taken in Beaverhead County by the USDA Agricultural Adjustment Administration in 1942, are located in one folder, while index sheets 60048-60052, created by the USDA Commodity Stabilization Service for Beaverhead County in 1955, are in the next folder. Finding aid entries for index sheets list their county location, producing agency, serial numbers, the date the aerial photographs were taken, and the current physical location of any corresponding aerial photographs.

Sub-series 3, Aerial Photographs, contains groups of aerial photographs that correspond with index sheets in Sub-series 2. Like the index sheets, the aerial photographs are arranged numerically by serial numbers assigned to each group of photographs prior to their arrival at The University of Montana. When index sheets and a group of aerial photographs match (i.e. cover the same geographical area, were produced by the same agency at the same time), they have the exact same serial number. Aerial photographs are listed in the finding aid by county location, date the photographs were taken and serial number. There are several index sheets in this collection with no matching aerial photographs and a few groups of photographs with no matching index sheet. When no corresponding aerial photographs or index sheets exist an entry in the container list has been added to indicate this fact.

Series II, Controlled and Uncontrolled Aerial Mosaics, contains individual oversized aerial mosaics produced by private aerial photography companies. Also included are two reference maps plotting the land area covered by each aerial mosaic. These items are not dated, but supplementary information suggests they were produced in the 1960s. Many of the items in this series have transparent overlays depicting geologic and historical information, such as the location of mineral deposits or old homesteads. This series is divided into two sub-series. Sub-series 1, Controlled Mosaics, includes all controlled mosaics as well as a reference map to the land area covered by each mosaic. Sub-series 2, Uncontrolled Mosaics, contains all uncontrolled mosaics and a reference map plotting their geographic location. Both sub-series are arranged numerically by serial numbers assigned to each mosaic prior to their arrival at the University of Montana-Missoula.

Series III, Geologic Plane Table Sheets, contains original geologic drawings of locations in Central Montana dating from 1920 through 1961. These drawings provide a wealth of geological, and often historical, information for each mapped location. Also housed in this series is a reference map that plots the location of each set of plane table sheets. This series is divided into sub-series based on the regional divisions of the reference map. The drawings are then arranged chronologically by date.