The records of the Royal Development Company document the operations of the Trinity Mine, located in the Chiwawa mining district in Chelan County, Washington.  The records span the period 1923-1946 with the bulk of materials dated pre-1936.  Timesheets and payroll records, daily, shift, and mill reports, supply and tally books, maps, and plans document the manpower and material required for copper production. Accident reports document the high number of  miners' injuries. There are also supply and tally books covering material stocked and bought at the company store.  These records are complete and cover the period between 1923 and 1933.  Also included in the records are manuals and catalogs from manufacturers.  The collection does not contain internal company correspondence or organizational records.

The maps and plans of the collection comprise an organizational chart of the company, daily reports of operations, profile and topographic maps of the mine and surrounding area, and several mechanical drawings of the equipment used at the mine.
 
The collection was found scattered on the floors throughout the Trinity Mine complex in the mid-1970s and shows deterioration from lack of adequate storage conditions..  Due to this factor most of the material is stained and fragile.  The contextual information is still available, however, and can be used to glean insights into the life and times of early 20th century miners and mining camps of Central Washington.