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

Yellowstone Caldera GPS Network - MAWY-Mammoth P.S.
Start: 14-Sep-2006
End: 14-Nov-2022
UNAVCO Community, 1999, Yellowstone Caldera GPS Network - MAWY-Mammoth P.S., UNAVCO, GPS/GNSS Observations Dataset, 
https://doi.org/10.7283/T50P0XCT

Yellowstone Caldera GPS Network - MAWY-Mammoth P.S.
Start: 07-Nov-1998
End: 14-Nov-2022
UNAVCO Community, Smith, Robert B., 1999, Yellowstone Caldera GPS Network - MAWY-Mammoth P.S., UNAVCO, GPS/GNSS Observations Dataset, 
https://doi.org/10.7283/T54F1P3J

Yellowstone Caldera GPS Network - MAWY-Mammoth P.S.
Start: 07-Nov-1998
End: 14-Sep-2006
Smith, Robert B., 1999, Yellowstone Caldera GPS Network - MAWY-Mammoth P.S., UNAVCO, GPS/GNSS Observations Dataset, 
https://doi.org/10.7283/T5VX0DV2