TY - RPRT TI - Methane-concentration and methane-isotope data for ground water and soil gas in the Animas River valley, Colorado and New Mexico, 1990-91 AU - Daniel T. Chafin AU - David M. Swanson AU - David W. Grey PY - 1993 DO - 10.3133/wri934007_1993 UR - https://pubs.usgs.gov/publication/wri934007_1993 ID - wri934007_1993 ER -