The Minnesota Correctional Facility in Stillwater has partially lifted a lockdown after some inmates refused to return to their cells on Sunday.
Full lockdown had been ordered for all of the prison's nearly 1,500 inmates.
Corrections officials said Tuesday that a lockdown is still in effect in the unit that was the site of the incident. That unit has about 280 inmates.
Another unit housing 223 inmates is on routine lockdown, which is a process officials use to search for contraband and perform maintenance.
Officials said the rest of the prison has returned to normal.