The L.M. Winsor Photograph Collection consists of 958 photographs and negatives that document Winsor's carreer as an irrigation specialist and flood control researcher. Collectively, the photographs show the step-by-step construction of many dams and flood control barriers, and chronicle the changing machinery and technologies used to build dams from 1915 to the early 1940s. Included in the images are many different irrigation and flood control projects, the surveying of the Bear River Migratory Bird Refuge, and photos of the Lake Mead area. Many of the photos are of Winsor's farm or projects in Enterprise, Utah. Also contains his report, "Utah's flood problem," and photos showing damage from various Utah floods and flood control projects, in particular the Willard, Utah flood of Aug. 13, 1923.

Box 1 documents the building of a dam at Enterprise, Utah from 1915 through 1918. Boxes 2 and 3 contain photographs and negatives in chronological order by year, from 1916 to 1941. Included in the images are many different irrigation and flood control projects, along with the surveying of the Bear River Migratory Bird Refuge. Box 4 is comprised mostly of unidentified prints. The photos in box 5 are part of a report submitted by Winsor to the Utah State Land Board. Although this report on Utah's flood problems was originally located in the manuscript collection (MSS 98), it was included because of the link with the photos in Box 5. Most photographs were given detailed captions by Winsor. An additional set of negatives and prints were included in 2024 (Box 4, folder 27).

L.M. Winsor's original captions were used where available to describe the images. His original numbering was also maintained in addition to our own numbering system. Within the first 3 boxes, there is an occasional empty envelope with a typed caption. These original envelopes were kept in the collection because they may correspond with photos in the L.M. Winsor manuscript collection (MSS 98). This collection also contains a box marked "Picture Index," but does not refer to photographs in this collection. All of the negatives appear to be made of nitrate cellulose. Box 3 also contains 57 negatives which are recent copies of existing photos and negatives from the L.M. Winsor manuscript collection.