A submarginal tract of a thousand acres on the Patuxent Research Refuge, Laurel, Maryland, was trapped for three seasons (1943-46) to determine the fur-productivity of the area. The tract yielded 392 fur animals, the pelts of which were sold at public auction for $1119.00. This resulted in an average income from trapping of approximately forty cents per acre per year. The habitats most productive of catches of fur animals were hedgerows and wood and road margins, followed by bottomland forests and lake margins. Some suggestions for improving habitat for fur animals are given.