The Mountain Lake Biological Station is located at approximately 4,000 feet altitude on Salt Pond Mountain, Giles County, Virginia. Since its establishment the Station has been a center for biological field research in southwestern Virginia. For work on lower vascular plants it is well located in that there are diverse habitats available within a half-hour’s drive from the station. A number of the existing problems concerning eastern American pteridophytes can be investigated in this area. This report contains the major results of a five-week intensive study, beginning on July 19, 1962. It is hoped that the information presented here will have, not only scientific value per se, but will contribute to teaching and encourage future research in this area. A number of new additions to the local pteridophyte flora were made during this study and these supplement the earlier reports of Massey (1960) and Thorne and Cooperrider (1960). Special attention was given to certain groups, especially Botrychium, Dryopteris, and Asplenium, and yielded interesting new information concerning their distribution and taxonomy. Several trips outside of Giles County were made, including one to Whitetop Mountain, which produced other new records which will be included here in the checklist for Giles Co. We also sought to collect and organize data on habitats, ecological variations, and breeding patterns, which will be described below. Voucher specimens from this study will be deposited in the herbaria of the U. S. National Museum, University of Michigan, Virginia Polytechnic Institute (Blacksburg), and the University of Virginia Biological Station.