The following information obtained from UNAVCO's online DOI system:
(https://www.unavco.org/data/doi/search/search.html)

Colorado Plateau/MAGNET - VFSP-VFSP P.S.
Start: 26-Jul-2010
End: 26-Sep-2020
Kreemer, Corne, Bennett, Rick, 2011, Colorado Plateau/MAGNET - VFSP-VFSP P.S., UNAVCO, GPS/GNSS Observations Dataset, 
https://doi.org/10.7283/T5CR5RJ0