This 1938 map of Seattle's Green Lake was included in a report on algae control for the lake, conducted by the WPA. The map highlights the relative depths, or bathymetry, of the lake as colors, in 5' increments, the dark blue showing depths of around 25' depth.
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Seattle's topography was a constant challenge to development and expansion and multiple regrades were implemented to sluice away hillsides using high pressure water cannons. The blow image shows an example of this c1910, via
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This c1885 view of the south shore of Lake Union, (which looks a little different today as the home of Amazon) shows the Western Mill Company (right) and Queen Anne Hill across the other side of the lake. Via @historylink.bsky.social Courtesy Washington State Digital Archives (AR-07809001-ph003736)