1/4 Scale Detail of Stair at End of Wing, Old Faithful Inn, Yellowstone National Park, 1927

1/4 Scale Plan of Porch and Main Stairs, Old Faithful Inn, Yellowstone National Park, 1927

12 Inch Butterfly Valve with 9 Inch Relief Outlet, D'Olier Engineering Company

12 Inch Butterfly Valve with 9 Inch Relief Outlet, D'Olier Engineering Company

12 Inch Butterfly Valve, D'Olier Engineering Company

1932 Master Plan, Yellowstone National Park

1933 Master Plan, Yellowstone National Park

1939 Master Plan, Yellowstone National Park

1940 Master Plan, Yellowstone National Park

1941 Master Plan, Yellowstone National Park

1942 Master Plan, Yellowstone National Park

1952 Master Plan, Yellowstone National Park

1954 Master Plan, Yellowstone National Park

1963 Master Plan, Yellowstone National Park

1965 Master Plan, Yellowstone National Park

1st Floor Plan, Lake Hotel, Yellowstone Park, Plan of Bed Rooms, 1919

2nd Floor, Lake Hotel, Yellowstone Park, Plan of Bed Rooms, 1919

3rd Floor, Lake Hotel, Yellowstone Park, Plan of Bed Rooms, 1919

A Boat House at the Lake, Yellowstone National Park, 1926

Addition to Canyon Cafeteria & Housekeepers Headquarters, Yellowstone Park Camp Company, 1935

Addition to Central Building, Canyon Camp, Yellowstone Park Camps Company, 1935

Addition to Dining Room, Old Faithful Inn, Yellowstone National Park, 1927

Addition to Girls Dormitory, Canyon Hotel, Yellowstone Park Hotel Company, Wyoming, 1929

Army Era: Buildings, Services, & Utilities

Army Era: Concessioners & Partners

Army Era: Land Survey & Boundary Maps

Army Era: Roads

Civilian Superintendents Era

Facilities & Maintenance: Buildings

Facilities & Maintenance: Roads & Trails

Master & Area Plans

Resource Management: Wildlife

Yellowstone National Park Heritage and Research Center