Following Garald Parker's long career in Florida hydrology, his materials focus almost exclusively on groundwater resources in southern Florida. The series labeled "Professional Papers" contains "Biographical Materials" which houses items about Parker's life, a box of "Correspondence" sent to or by Parker, "Educational Materials" which contains Syllabi and handouts used by Parker during his teaching career, two boxes of "Legal Papers" which deal with extensive materials Parker collected relating to two court cases, "Organization and Association Records" for environmental and science societies Parker followed, and the two "Projects" boxes which are organized around certain cases and may contain correspondence, reports, or court documents. "Professional Papers" also contains three boxes labeled "Writings" boxes cover articles and other writings by Parker.