Modification of Restricted Areas R-6501A and R-6501B; Underhill, VT

This action modifies restricted areas R-6501A and R-6501B, Underhill, VT, by amending the upper altitude limit of R-6501A and the lower altitude limit of R-6501B. Certain military activities near Underhill, VT, require restricted airspace that exceeds the current 4,000-foot mean sea level (MSL) upper altitude limit of R-6501A. As a result, R-6501B must be activated, along with R-6501A, to ensure containment of the hazardous activity. Raising the upper altitude limit of R-6501A from 4,000 feet MSL to but not including 4,900 feet MSL and the lower altitude limit of R-6501B from 4,000 feet MSL to 4,900 feet MSL, will result in more efficient use of airspace by reducing the need to activate R-6501B. This modification is fully contained within the existing lateral and vertical limits of R-6501A and B. The activities conducted in these restricted airspace areas are unchanged.