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

Southern Basin and Range GPS Network - ECHO-Echo P.S.
Start: 29-May-1999
End: 11-May-2005
Wernicke, Brian P., 1999, Southern Basin and Range GPS Network - ECHO-Echo P.S., UNAVCO, GPS/GNSS Observations Dataset, 
https://doi.org/10.7283/T5C24TR7

Southern Basin and Range GPS Network - ECHO-Echo P.S.
Start: 29-May-1999
End: 14-Nov-2022
UNAVCO Community, Wernicke, Brian P., 1999, Southern Basin and Range GPS Network - ECHO-Echo P.S., UNAVCO, GPS/GNSS Observations Dataset, 
https://doi.org/10.7283/T5MK6B7T

Southern Basin and Range GPS Network - ECHO-Echo P.S.
Start: 11-May-2005
End: 14-Nov-2022
UNAVCO Community, 1999, Southern Basin and Range GPS Network - ECHO-Echo P.S., UNAVCO, GPS/GNSS Observations Dataset, 
https://doi.org/10.7283/T5GT5KH3