Update 2:10 p.m. Tuesday
The lockdown at the Laurel Middle School was lifted shortly after 2 p.m.
The school district said police determined the threat was not credible.
Normal school activities were to be resumed and students were to be dismissed at regular times.
Laurel police said that one caller seemed to have placed a threatening call to multiple agencies, including in Yellowstone County and West Yellowstone.
LAUREL - The Laurel School District sent a message Tuesday afternoon to parents and guardians that the Laurel Middle School is on a "hard lockdown."
The message sent shortly after 1:30 p.m. stated the lockdown was "due to a potential threat that is being investigated by the Laurel Police Department."
"We will communicate with you when more information as it becomes available," the message states. "All students are safe, please do not call the school or district for more information as we need phone lines open."
This is a developing story. Check back for updates.