2:47 p.m. Update: an email from Principal Miller says the lockdown will end around 3 p.m.

HHS Community,
We are ending our Lockdown in about 10-minutes. Everything went according to our protocols and the police were amazing. We had a few students indicate they had a firearm and were going to conduct a "school shooting". We identified the students and are working on next steps with police. I am going to hold an all school assembly  at 3:00 to talk to our students and staff about what occurred and send everyone home on time.
Judson Miller
Principal

2:35 p.m. Update: scanner says two suspects are in custody, no shots fired. Principal Miller has sent a second email: 

Hellgate Parents:

We are still in lockdown, waiting for police to complete the initial investigation of the issue.  As soon as they have determined that it is safe, we will release from lockdown.  We anticipate that will happen soon.  All students are safe in lockdown at this time.  We will update you soon.

2:21 p.m. Update: according to our police scanner, MPD have a suspect in custody, but that is not confirmed by our news department.

My son is on lockdown at Hellgate High School. Although I know in my heart that everything is going to be OK, I'm shaking and feel obligated to share with families what we know so far.

Oliver texted me at 1:27 this afternoon to let us know Hellgate went into lockdown following reports of a firearm on campus, this was later confirmed in an email from Principal Judson Miller at 1:57 p.m.

I drove by on my way to do my Blaze show, just before 2 p.m. and traffic was rerouted and there were dozens of cops surrounding the Hellgate High School neighborhood. As I type this at 2:20 p.m., students and faculty are still sheltering in place and we will keep you up to date. See below for the email from the principal in it's entirety.

HHS Community,
Our school went into lockdown at 1:24 today based on a report that there was a firearm on campus. We are working with Law Enforcement and our camera system. As of now, the report is unsubstantiated. Police are on site and we are working through our protocols. I will provide updates soon.
Judson Miller
Principal

An alert also went out to U of M students and faculty:

Hellgate Highschool is currently LOCKED DOWN.  There is a lot of law enforcement traffic & activity in the area.  Please stay clear of the area until the situation is cleared.  There is currently no know threat to the University of Montana Campus.  Fraternities and Sororities on Gerald should avoid Hellgate High School.  A follow-up message will come once more information is received.

67 School Age Montana Kids Missing Right Now