This collection consists of a single diary maintained by Olive Graef Treat, a resident of New York, Chicago, and Seattle; and wife of Harry W. Treat, a successful mining venture capitalist. The entries commence in Chicago on January 1, 1897 and continue through the year nearly uninterrupted. The first diary entry is in a different hand--presumably that of Harry W. Treat--and during two occasions of a week or more in which Olive Treat did not have access to the diary, entries were made by her husband (whom Olive Treat refers to as "Kim"). The diary entries focus largely on social activities, Harry Treat's mining business activities, travel, family, and the weather.

Though the diary begins with the Treats in Chicago, much of their year was spent traveling: a month was spent with family in New York beginning in mid-January; another month in British Columbia, as Harry Treat oversaw operations at his mine at Van Anda; and another trip to New York via Quebec in mid-summer. The Treats left for New York again in September and seem not to have returned to Chicago for the remainder of the year. The New York diary entries make frequent mention of recreation (boat races, tennis and croquet) and entertainment, including the many theatrical productions that Olive Treat attended. The entries made in British Columbia frequently mention details of her husband's mining business, in which Olive Treat was actively interested. The collection also contains a few loose materials that had been inserted in the diary, including three photographic portraits of the Treats and several small pencil sketches.