A Geophysical Study of North Park and the Surrounding Ranges, Colorado Behrendt, John C. ; Popenoe, Peter ; Mattick, Robert E. Abstract Publication: Geological Society of America Bulletin Pub Date: 1969 DOI: 10.1130/0016-7606(1969)80[1523:AGSONP]2.0.CO;2 Bibcode: 1969GSAB...80.1523B