Austin Post C. S. Brown David Frank S. M. Hodge L.R. Mayo Lowell A. Rasmussen E.A. Senear W. G. Sikonia D.C. Trabant R.D. Watts Mark Frederick Meier 1978 application/pdf 10.3133/ofr78264 en U.S. Geological Survey, Columbia Glacier progress report; December 1977 reports