The sectionals show that area as SUA:
View attachment 75746
Furthermore, the NOTAM for R-4006:
R-4006 Patuxent River, MD Boundaries. Beginning at lat. 38°41'15"N., long. 75°45'59"W.; to lat. 38°32'30"N., long. 75°43'44"W.; to lat. 38°19'00"N., long. 75°36'59"W.; to lat. 37°55'00"N., long. 75°52'29"W.; to lat. 37°45'00"N., long. 75°58'44"W.; to lat. 37°45'00"N., long. 76°23'29"W.; to lat. 37°50'30"N., long. 76°31'59"W.; to lat. 38°05'10"N., long. 76°34'14"W.; to lat. 38°11'10"N., long. 76°25'09"W.; to lat. 38°30'00"N., long. 76°03'59"W.; to lat. 38°36'00"N., long. 75°55'29"W.; along the Pennsylvania Railroad to the point of beginning, excluding R-4002, R-4005, and R-6609. Designated altitudes. 3,500 feet MSL to but not including FL 250.
Time of designation. 0700-2300 local time, daily; other times as specified by NOTAM.
Controlling agency. FAA, Washington ARTCC.
Using agency. U.S. Navy, Commanding Officer, NAS Patuxent River, MD.''
AMENDMENTS 1/13/11 75 FR 68970 (Amended)
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Commercial and recreational UAS pilots: restricted and prohibited areas, active temporary flight restrictions (TFRs), and the Washington, DC Flight Restriction Zone (FRZ) are shown in red. UAV flights are not allowed in these areas without explicit permission.