Come join us as a past president of both the Health Physics Society and the American Academy of Health Physics chronicles the life and legacy of Herbert M. Parker and how his contributions have impacted the parallel professions of medical and health physics.  Herbert Parker was personally selected as the best possible choice to cope with the extraordinary problems associated with plutonium production at Hanford plutonium production site to which he transferred in the summer of 1944.   Here, Parker developed a highly successful radiation protection program.  He calculated the first DAC, derived for plutonium, and new quantities and units for physical and biological dose that live on today as the direct ancestors of the modern gray and sievert.  Remaining at Hanford after the war, he was instrumental in creating and managing the Hanford Laboratories whose contributions to radiological health and environmental protection ones, achieved world renown.