Prepared in 1963, this plan for the rural valleys outside Baltimore is the first long-range development plan based on the application of principles of ecological determinism and has become a prototype for similar urbanizing areas. This study developed the tools of environmental planning for which WMRT, now WRT, has become renowned combining ecological and socioeconomic planning methods to discern the most intrinsically suitable pattern and scale of development. The plan was adopted by Baltimore County and the Regional Plan Commission and to this day has conserved the character of an extraordinary landscape.