Dale Heckendorn No description specified. 1-4 (4 Records) Documents Colorado Preservation 2000: Enriching Our Future By Preserving Our Past (Draft 11) (1995) Denver Municipal Auditorium: Source Material (1999) Ornamental Concrete Block Buildings in Colorado 1900-1940 (1997) Ornamental Concrete Block Buildings in Colorado, 1900 to 1940 (1997)