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

Rio Grande Rift GPS Network - RG19-RG19Bison_CO2006 P.S.
Start: 02-Aug-2006
End: 18-Jan-2018
Sheehan, Anne, 2006, Rio Grande Rift GPS Network - RG19-RG19Bison_CO2006 P.S., UNAVCO, GPS/GNSS Observations Dataset, 
https://doi.org/10.7283/T557198G