The university in Jonesboro, about 130 miles northeast of Little Rock, said in a statement the school was placed on lockdown after the suspect crashed the vehicle on campus.
"Man in custody at ASU. Officers in process of securing vehicle now," the Jonesboro Police Department said on its Twitter feed, without providing further details.
The school has kept the lockdown in place as police investigate the scene, it said on its Twitter feed.
The Arkansas Democrat-Gazette published a photo of a pickup truck with an American flag flying from near the tail, saying it was the suspect's vehicle. The pickup is seen stopped near a walkway and by a paved area with tables and benches.
Other photos on social media showed the man brandishing a shotgun and draping what appeared to be a "Don't Tread on Me" flag on his truck.
The Jonesboro Sun reported police as saying the suspect had two propane tanks in the back of the pickup truck.