There is hereby authorized to be appropriated, for construction of the Blue Ridge Parkway extension, not more than $87,536,000, plus or minus such amounts, if any, as may be justified by reason of fluctuations in construction costs as indicated by engineering cost indices applicable to the type of construction involved herein.
16 USC § 460a-11
Authorization of appropriations
through Pub. L. 116-344, except Pub. Ls. 116-260 and 116-283