Prison officials placed Stony Mountain Institution on lockdown Friday night to conduct a number of searches.
Just after 6 p.m. the medium-security prison was put into lockdown after prison officials seized "unauthorized items" from inmates.
Officials said the search was necessary to ensure the staff and inmates were safe.
Stoney Mountain won't reopen until the search is complete and the prison is safe, which could be as late as Sunday, officials said.
Officials from the institution said inmates are subject to lockdown at least twice a year.
