Engineer, City of Seattle, Park Department, Seattle, WA, c. 1949;

Hall worked with Edward Johnson, Director of the Woodland Park Zoo in 1949, to build a new bear exhibit at the Woodland Park Zoo in 1949. This exhibit was to provide new homes for 5 large and 2 small bear species. This enlarged grotto area, as large as a city block, was to cost $250,000, to be paid for by a $2.5 million Park Department bond issue passed in 1948.