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

Yellowstone Hotspot GPS Network - NOMT-Norris Montana P.S.
Start: 16-Sep-2006
End: 14-Nov-2022
UNAVCO Community, 2000, Yellowstone Hotspot GPS Network - NOMT-Norris Montana P.S., UNAVCO, GPS/GNSS Observations Dataset, 
https://doi.org/10.7283/T5FT8JCQ

Yellowstone Hotspot GPS Network - NOMT-Norris Montana P.S.
Start: 02-May-2000
End: 14-Nov-2022
UNAVCO Community, Smith, Robert B., 2000, Yellowstone Hotspot GPS Network - NOMT-Norris Montana P.S., UNAVCO, GPS/GNSS Observations Dataset, 
https://doi.org/10.7283/T5B27SN9

Yellowstone Hotspot GPS Network - NOMT-Norris Montana P.S.
Start: 02-May-2000
End: 16-Sep-2006
Smith, Robert B., 2000, Yellowstone Hotspot GPS Network - NOMT-Norris Montana P.S., UNAVCO, GPS/GNSS Observations Dataset, 
https://doi.org/10.7283/T56D5R9V