The Broadway Bridge was opened in 1913. It is a Rall-type Bascule Bridge. Each side opened up to allow river traffic. When built, it had streetcar tracks install for the Broadway Line streetcar linking downtown Portland with East Portland. Streetcar service ended in 1940. From 1937 through 1958, Electric Trolley Buses ran over the bridge. ETB's are buses with trolley poles, as they get their power from overhead wires instead of diesel engine. Starting in 2012, the streetcar returned to the Bridge with the modern Portland Streetcar. Today the Loop A and B lines run over the bridge in addition the Trimet Bus route 17.
The cache hide large pedestrian safety triangle. The old looking green poles in the triangle were used to hold up the trolley bus wires. Surprisingly they are still here. One of them may even conceal a geocache....