Google Maps: Here is the area of the standoff.

UPDATE (2:34 AM):

Officer Zack Winter tells K2 Radio News that the situation is over and the suspect is in custody. There is no longer any threat to the community.

We will have more details later today.

UPDATE (2:19 AM);

The gunshot sound was actually a flash-bang grenade. No word on how or why it was deployed.

UPDATE (2:12 AM):

Sgt. Chris Hadlock of the Casper Police Department told reporters that the situation is under control and there is no danger to the community.

Our reporter says that just as he finished the statement, there was a gunshot. We don't know yet who fired but will update when more information is available.

UPDATE (12: 29 AM):

Spectators and reporters have been moved back from the scene.

WYDOT confirms that I-25 has reopened.

One report into K2 Radio News from a witness says the car the man originally drove was full of bullet holes.

Glenrock Independent is reporting that there was originally a female accomplice and she is now in custody.

UPDATE (12:16 AM):

Special Response officers have moved their lines nearer the vehicle occupied by the suspect. Loudspeakers are being used to communicate, in stern terms, with the man in the car. One was heard telling the man, "We don't want to kill you."

In a related development, the Code Red warning to citizens in Glenrock has been lifted.

UPDATE (11:56 p.m.):

Our reporter at the scene says law enforcement has established a significant presence outside Dayton Transmission, and authorities are apparently setting up a command center at roughly the intersection of Elma and F Street. 

Officers are using a bullhorn to communicate with someone in a car, who is evidently a suspect in tonight's incident. 

Check back for updates. 

UPDATE (11:22 p.m.):

A source tells K2 Radio that a police standoff is taking place at Dayton Transmission, located in the 1600 block of East F Street in Casper on the north side of I-25. 

Reportedly, no one has been injured in that standoff. We are pursuing further details.

I-25 is closed to eastbound and westbound traffic between Wyoming Boulevard and Poplar. 

The notice from Glenrock police, posted to the department's Facebook page earlier tonight, has been removed. 

Check back for updates as this situation develops. 

======================================================

UPDATE (10:57 p.m.):

Signs over Interstate 25 warn of an armed fugitive on the loose.

A state trooper in the area confirmed to K2 Radio that a gun was involved, though the nature of the incident has not been detailed further. 

Drivers on I-25 were told by authorities to exit the interstate. An ambulance was reportedly waiting near one exit in Douglas. 

Glenrock police have been unable to provide any updates, as all officers are involved in the current situation. 

Traffic on I-25 westbound was stopped for some time in the area of exit 187. Eastbound traffic through Casper at this point seems to be flowing. 

A significant number of law enforcement officers from at least four different agencies have been seen in the area. K-9 units are reportedly working the incident as well. 

Check back for updates. 

====================================================

Original Story:

Glenrock residents are being asked to stay inside and lock their doors.

The Glenrock Police Department posted the warning on their Facebook page shortly before 10:30 p.m. Saturday.

Casper residents reported significant law enforcement presence in Casper near Interstate 25 at roughly 9:30 p.m. Casper police dispatch advised the incident is under the supervision of the Wyoming Highway Patrol, which has not yet returned a call seeking details.

We're pursuing more information. Check back for updates.