The collection consists chiefly of maps, blueprints, legal documents, and correspondence related to the dispute between the City of Long Beach and the Union Pacific Railroad (and various other property disputes) regarding the location of the tideland boundary line and the revenue generated from the sale or disposition of oil, gas, etc from the tidelands. The collection also documents the construction of the Aliso St. Viaduct in the 1930s.

Highlights of the collection include photostats of maps and early Rancho documents procured by surveyor Francis Bates, as well as field notes by Henry Hancock in the 1850s. One particular document is a certified copy (with official seal) of Field Notes of the Final Survey of the Rancho San Pedro, Don Manuel Dominguez, Confirmee, by Henry Hancock, Deputy Surveyor, Under his instructions of December 11, 1857. Similar documents are included for [Ranchos] Los Cerritos, Los Alamitos, Las Bolsas, San Antonio, Los Coyotes, La Bolsa Chica, and Santa Gertrudes.