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

Colorado Plateau/MAGNET - ROXY-ROXY P.S.
Start: 01-Aug-2010
End: 25-Sep-2020
Kreemer, Corne, Bennett, Rick, 2011, Colorado Plateau/MAGNET - ROXY-ROXY P.S., UNAVCO, GPS/GNSS Observations Dataset, 
https://doi.org/10.7283/T51R6NQ8