No. 76-1100. Argued and Submitted November 18, 1976. Decided December 23, 1977. James E. Hautzinger, Denver, Colo. (Charles W. Newcom of Dawson, Nagel, Sherman Howard, Denver, Colo., on the brief), for petitioner. Andrew F. Tranovich, Atty., N.L.R.B., Washington, D.C. (John S. Irving, Gen. Counsel, John E. Higgins, Jr., Deputy Gen. Counsel, Carl L. Taylor, Associate Gen. Counsel, Elliott Moore, Deputy Associate Gen. Counsel, N.L.R.B., Washington, D.C., on the brief), for respondent. Peggy A. Hillman