Hart stereoview of a Pullman Palace Dining Car, with building supplies and other equipment in the foreground

Have not seen this Hart stereoview of a Pullman Palace Dining Car before. Can anyone say where this Hart view was taken, the date, or identify the structure and construction materials in the foreground?

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Pullman Palace Dining Car, with building supplies and other equipment in the foreground.
Taken on the CP Sacramento wharf, under construction, June 19, 1869.
Untitled Alfred A. Hart CPRR strereoview detail from the series "Scenes in the Valley of the Sacramento."

Images Courtesy of Alan Wohlleben.