DIRECTOR, U. S. B. OF M. v. PRINCESS ELKHORN COAL CO.

Attorney(s) appearing for the Case

John G. Laughlin, Washington, D. C., argued Warren E. Burger, Asst. Atty. Gen., Melvin Richter, John G. Laughlin, Dept. of Justice, Donald G. Welsh, Dept. of Interior, on the brief, for appellant.

John K. Pickens, Jerry N. Griffin, M. Joseph Stoutenburgh and John C. Gall, Washington, D. C., on the brief, Dawson, Griffin, Pickens & Bird, Gall, Lane & Howe, Washington, D. C., of counsel, for appellee.

Welly K. Hopkins, Harrison Combs, Willard P. Owens, Washington, D. C., on the brief, amicus curiae, for United Mine Workers of America.

Ed D. Schorr, Columbus, Ohio, Louis J. Schneider, Jr., Cincinnati, Ohio, on the brief, amicus curiae, for Operators & Committee on Federal Mine Safety Legislation.

Before MARTIN, McALLISTER and MILLER, Circuit Judges.