Except for certain portions of the area, deemed to be especially adaptable for recreational uses, particularly swimming, boating, sailing, fishing, and other recreational activities of similar nature, which shall be developed for such uses as needed, the said area shall be permanently reserved as a primitive wilderness and no development of the project or plan for the convenience of visitors shall be undertaken which would be incompatible with the preservation of the unique flora and fauna or the physiographic conditions now prevailing in this area . . .

(Aug. 17, 1937, ch. 687, Sec. 4, 50 Stat. 670; June 29, 1940, ch. 459, Sec. 1, 54 Stat. 702; Mar. 6, 1946, ch. 50, 60 Stat. 32.)