Originally Lake Union was one-third larger than it is today. A small bay extended inland to Mercer Street and a stream ran through and around Boren Avenue. South Lake Union is situated in an area that long played a vital role in Seattle’s history. Native Americans were the early settlers of South Lake Union and it was a trailhead for major trails headed for Elliott Bay and the Duwamish River. Early European settlers found several Indian camps on the shoreline near Westlake. David Denny, an original Seattle pioneer, claimed land in 1853 extending from Mercer to Denny Way. With these pioneers came industry and quickly the once heavily wooded area was cleared. With the arrival of the first sawmill came the beginning of the filling of the lake. Mills dumped sawdust into the water, covering the small bay at the southwest corner of the lake. The Cascade community, one of the original Seattle residential communities, is the eastern flank of the South Lake Union area. Properties in South Lake Union display a unique architecture of the working 1920’s. Warehouses were built for manufacturing, storage and service. One can clearly view the transition from brick, timber framed buildings to concrete and brick structures; some of Seattle’s first reinforced concrete structures were built in South Lake Union. Also prevalent are numerous examples of post and beam construction, which have proven to be very adaptable to reuse. Buildings display a refreshing variety of decoration, including excellent examples of terra cotta, ornate brick patterns, and multi-pane industrial windows.