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

SCIGN USGS GPS Network - UCSB-UC Santa Barbara P.S.
Start: 08-Oct-1998
End: 12-Feb-2016
Hudnut, Kenneth, King, Nancy, Aspiotes, Aris G., Borsa, Adrian A., Determan, Daniel N., Galetzka, John E., Stark, Keith F., 2006, SCIGN USGS GPS Network - UCSB-UC Santa Barbara P.S., UNAVCO, GPS/GNSS Observations Dataset, 
https://doi.org/10.7283/T59P2ZWH