WALNUT CREEK, Calif. (AP) – That mustang in the rearview mirror turned out to be a real horse running on a Northern California highway – followed by a mule.

Commuters east of San Francisco on Monday were stunned to see a white horse and a brown mule running across Interstate 680.

READ MORE: Police Investigating Strip District Shooting, Man Left In Critical Condition

Steve Burdo with Contra Costa County Animal Services says the animals broke through a fence about a mile away.

The pair adhered to the vehicle code and used an on-ramp to enter the highway.

READ MORE: Anthony Gonzalez, House Republican Who Voted To Impeach Pres. Trump Won't Run Again

Authorities shut down lanes shortly before 7:30 a.m. as motorists shot cellphone video and officers rounded up the four-legged fugitives.

Burdo says the horse, a gelding named Striker, appears to have led the breakout. He says Hank the mule is more of a follower.

Join The Conversation On The KDKA Facebook Page
Stay Up To Date, Follow KDKA On Twitter

MORE NEWS: COVID-19 Deaths In West Virginia This Month Double That From August

(Copyright 2017 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.)