SCRUBGRASS TWP, Venango County — A portion of Interstate 80 was a scene of udder gridlock Thursday night as a small herd of dairy cows escaped an overturned trailer and hoofed it down the highway near the Venango-Butler county line.

The cattle call shortly before 6:30 p.m. near the Emlenton Bridge proved challenging for police and firefighters tasked with coaxing and corralling the dozens of, at times, bullheaded bovines.

Westward traffic was finally restored six hours later, authorities said.

“It was funny at first,” said Barry Louise, assistant fire chief for the Emlenton Volunteer Fire Department, “but then we all got tired of doing it.”

The impromptu round up began after a double-decker cattle truck hauling 30 cows tipped over on its driver’s side while traveling west on I-80 in Scrubgrass Township. Some of the cows made a break for it; some remained on the 50-foot-long trailer.

Five of the cows died in the crash or had to be euthanized due to injuries they suffered.

In all, 10 to 15 cows were on the loose. Two were still missing this morning. They were last seen on Squaw Valley Road, Allegheny Township, about a mile from the crash site.

The driver, James Gambrel of Ohio, suffered minor injuries.

The makeshift drovers, which included seven or eight troopers and 30 or so firefighters, still had not gotten the upper hand by 8:30 p.m. when PennDOT decided to expand the lane closures.

During the roundup, fire crews parked their engines and rescue trucks around the cows to form improvised corrals to cajole them into a series of trailers provided by Hovis Towing in Emlenton and Hirsch Meats near Knox.

Westbound lanes did not reopen until about 12:40 a.m. today.

Police this morning did not say if the driver would face any violations.