John S. Delano and Joseph Workman Dwyer were owners of the D & D Ranch. Dwyer, a Washington D.C. official, moved to New Mexico in 1876, and began raising sheep at Uña de Gato Creek. He and Delano then became partners in a large-scale cattle enterprise, also known as the D & D Ranch Co., at Johnson's Mesa. In 1892, Dwyer sold out to become involved in real estate.

The collection comprises recording books containing livestock branding records and accounts of the operation and maintenance of the ranch in Otero, Colfax County, NM. Some may also apply to Dwyer's Uña de Gato Ranch. Volume one (1877-1883) contains stock accounts of cattle, horses and sheep, with records of brands, ages, sex, deaths, purchases and sales. Also includes cash ledgers for Delano and Dwyer, and itemized accounts by name and duties of individual employees. Volume two, inscribed "Uña de Gato Book" on the cover, records totals of cattle on hand, branded and sold for the beginning of each year from Jan. 1, 1886 to Jan. 1, 1891. Volume three is a tally book of brands noted by location or outfit, for May through July 1887. Front endpaper is inscribed "Delano & Dwyer Round up Outfit."