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

Alaska GPS Network - CLGO-College Observatory P.S.
Start: 06-Apr-2005
End: 14-Nov-2022
UNAVCO Community, 1998, Alaska GPS Network - CLGO-College Observatory P.S., UNAVCO, GPS/GNSS Observations Dataset, 
https://doi.org/10.7283/T5DR2SJK

Alaska GPS Network - CLGO-College Observatory P.S.
Start: 11-Mar-1996
End: 06-Apr-2005
Freymueller, Jeffrey T., 1998, Alaska GPS Network - CLGO-College Observatory P.S., UNAVCO, GPS/GNSS Observations Dataset, 
https://doi.org/10.7283/T5P55KJV

Alaska GPS Network - CLGO-College Observatory P.S.
Start: 11-Mar-1996
End: 14-Nov-2022
UNAVCO Community, Freymueller, Jeffrey T., 1998, Alaska GPS Network - CLGO-College Observatory P.S., UNAVCO, GPS/GNSS Observations Dataset, 
https://doi.org/10.7283/T5JH3J7V