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

Southwest Montana GPS Network - WPRG-White Pine Ridge P.S.
Start: 18-Sep-2011
End: 10-Aug-2016
Bendick, Rebecca, 2011, Southwest Montana GPS Network - WPRG-White Pine Ridge P.S., UNAVCO, GPS/GNSS Observations Dataset, 
https://doi.org/10.7283/T51V5BWF