TY - RPRT TI - Transient electromagnetic soundings in the San Luis Valley, Colorado, near the Great Sand Dunes National Park and Preserve and the Alamosa National Wildlife Refuge (field seasons 2007, 2009, and 2011) AU - David V. Fitterman PY - 2017 DO - 10.3133/ds1043 UR - https://pubs.usgs.gov/publication/ds1043 ID - ds1043 ER -