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

PBO GPS Network - P430-Elma_Elem_WA2005 P.S.
Start: 10-Apr-2005
End: 27-Jun-2017
UNAVCO Community, 2005, PBO GPS Network - P430-Elma_Elem_WA2005 P.S., UNAVCO, GPS/GNSS Observations Dataset, 
https://doi.org/10.7283/T5DF6P5T