O. L. kept a daily diary from 1895-1951. Due to Peterson's discerning eye for detail, his entries in his journals are tremendous. This set of diaries gives a marvelous description of an early dry farming operation in Cache Valley and its development during a rapidly changing period of agricultural growth at the turn of the century. Peterson kept an thorough account of the daily farm routine. Additionally, he noted the seasonal occurrences of plowing, planting, harvesting, and winter livestock care. Besides these entries, he often ended the year with an inventory of equipment, livestock, and the amount of feed stored for winter. For example, in the 1903 volume (Box 1, Folder 10) he listed all of the farm machinery on the farm, when each machine was purchased and how much was paid for it. The same volume also inventories the livestock and even goes as far as stating the names and weights of the horses. Box 1 Folder 1 contains a ‘daybook', which spans the period of 1895 to 1915 and presents an overview of Peterson thoughts and labor.

The diaries, as one would suspect, contain detailed information about the operation of the farm. Important social and political occurrences are mentioned, but without any comment about his feelings toward those events. He does, however give an excellent record of weather conditions and of natural occurrences, such as earthquakes. The diary also describes the physical geography of the Petersboro-Benson area, especially for the pre-Cutler Dam period. O. L. also comments on the flora and the fauna of the area as well.

This collection has been organized chronologically. However, there are two variations to this organization. First, O. L. apparently wrote out a draft of his entries on loose-leaf paper, and then at his leisure would enter the notes into the bound volumes. Some of these loose-leaf notes are part of the collection and have been placed into folders and integrated into their appropriate place. During the years 1895-1916, Peterson kept a volume that had a short synopsis for each day, which essentially indexes this 21-year period. Finally, a portion of the diaries, for the years 1925 to 1940 (except for a incomplete run during 1926), were absent from the original donation given to USU Special Collections & Archives.