When The Who stopped traffic at Merriweather Post Pavilion

Of all the artists to play Merriweather Post Pavilion through the years, one brought concert traffic to its knees. In 1970, a performance by a British rock group snarled roads and triggered six-mile backups of anxious fans on Route 29 near Columbia.

The group? The Who. On June 29, a young, free-spirited crowd of 20,000 — nearly twice capacity — jammed the pavilion to hear The Who, a storied act led by Pete Townshend and Roger Daltry and known for hits like “Magic Bus,” “I Can See For Miles” and the rock opera, “Tommy.” Those without tickets were admitted for free.

The Washington Post called the concert “a mini-Woodstock” peopled by “an incredible mass of flesh.” Just reaching the site by car proved a challenge.

“Somewhere around the Scaggsville Super Market [six miles away], you could catch second gear; otherwise, just a few miles off the [Capital] Beltway, it was first gear only,” The Post reported. “Campers, panel trucks, bikes, muscle cars and the ubiquitous [Volkswagen] Beetle stood bumper to bumper … along the road to the entrance.”

Some folks gave up, ditched their cars three miles away and hoofed it.

“People were still trying to get in as [others] drove out [to beat the crowd] a few minutes before the concert ended,” The Post reported. Three hours later, at 1:30 a.m., the last cars departed. Despite the numbers, there had been no arrests. Musicgoers “even left their trash in neat piles,” a concert spokesman said. Law enforcement officers were less effusive.

“If they [pavilion brass] want to make a chicken coop out of their theater, that’s their prerogative,” a Maryland State Police official said.

Fifty-two years and 100 million record sales later, The Who is still touring and will perform May 23 at the Capital One Arena in Washington.