Following the release of the final regional lease sale environmental impact statement, and prior to adopting a regional lease sale schedule, the Secretary shall engage in formal consultation as specified in Sec. Sec. 3420.4-2 through 3420.4-5 of this title. [44 FR 42615, July 19, 1979. Redesignated and amended at 47 FR 33139, July 30, 1982]