Between 1897 and 1930, Seattle’s hilly terrain underwent radical regrading, perhaps the most significant alteration of urban terrain at the time. Regrading in Seattle was adopted mainly for economic reasons. By reshaping the land, more commerce could flow into the city. Initially, city planners believed that business would thrive if the streets were at regular angles and at a level elevation. The city of Seattle was built by moving mountains, straightening rivers, leveling hillsides, digging sewers, paving roads, and carving canals. In his 1916 History of Seattle, Clarence Bagley wrote that “no great city on the American continent has overcome so many natural obstacles in its expansion.” Bagley concluded that Seattle was a “vast reclamation project.”
During regrading in Seattle, starting in 1897 and continuing through 1930, the hilly topography of central Seattle was radically altered
Denny Hill is slowly washed away by powerful water cannons. 1910.
These regrading projects began after the 1889 fire that destroyed much of Seattle’s downtown retail district. After the blaze, City Engineer R. H. Thomson initiated an ambitious plan to reinvigorate the city. He convinced the municipal government to level hills, fill tidelands, straighten the Duwamish River, and purchase the Cedar River watershed. Most of these projects were completed between 1890 and 1930, when Seattle matched Bagley’s description of a city under near-constant construction.
The Denny Hotel (later called the Washington Hotel) stands on the south summit of Denny Hill before being torn down. 1905.
Seattle completed several regrading projects, but one of the most notable was the Denny Regrade, completed in two phases. During the first Dennis Regrade (1908–1911), about 27 city blocks were removed from Pine Street to Cedar Street and Second to Fifth Avenues. Approximately 20,000,000 US gallons (75,708 m3) of water was pumped daily from Lake Union, aimed at the hill, and then run through tunnels to Elliott Bay.
Trains move loose earth at the south summit of Denny Hill near the under-construction New Washington Hotel, at the corner of Second Avenue and Stewart Street. 1907.
Third Avenue north of Marion Street is flattened out in the first Denny regrade. 1907.
Looking west down Spring Street during the first Denny regrade. 1907.
Horse teams march up Marion Street. 1907.
Looking south from Third Avenue and Madison Street. 1907.
A few “spite mounds” stand amid the flattened remains of Denny Hill. 1909.
The remains of Denny Hill. 1909.
Leveling streets in Seattle.
Steam shovels dig near the Jose P. Rizal bridge during the Dearborn regrade. 1912.
The Ross Shire Hotel on Sixth Avenue and Marion Street. 1914.
A steam shovel digs on Marion Street during the Sixth Avenue regrade. 1914.
A conveyor belt carries earth from the dig site to the harbor. 1930.
A crowd gathers to witness the last shovel of dirt and the completion of the second Denny regrade.
A conveyor belt for moving earth at Fifth Avenue and Battery Street.
A conveyor belt carries earth from the dig site down Battery Street to the harbor.
A postcard shows the Washington Hotel atop Denny Hill before Denny Regrade No. 1 and the New Washington Hotel (the dark building in the lower picture, now the Josephinum) built on the newly leveled land.
Railroad Avenue, today’s Alaskan Way, depicted here in 1900, was built on fill from the early regrades. To the right in this picture, casting shadows, are the wharves of the Central Waterfront.
A tugboat tows a skow full of earth out into the harbor.
A self-capsizing scow carrying earth dumps its load into the city’s harbor.
Photo credit: Library of Congress / Seattle Municipal Archives / Wiki Commons