Loyal deadheads have been cooling their heels for a long time in anticipation of Dead & Company returning to Shoreline Amphitheatre, but they weren't expecting this kind of wait.

Concert-goers hoping to see the Grateful Dead spinoff band on June 1 say they ended up waiting in line for more than two hours to get through an understaffed security checkpoint to enter the show. Deep into the jam band's set, hundreds if not thousands of ticket-holders were still outside waiting to get in the amphitheater.

Scott Wiener, a physician from Southern California who traveled to Mountain View for the show, said he arrived more than an hour before the Dead & Company's 7 p.m. scheduled start time. By that point, he estimated the queue of people waiting to get inside the venue was nearly a mile long. It soon became clear the line was barely moving, he said.

As the minutes ticked by, the Deadhead crowd became crestfallen as it became clear they might miss the show. Some fans attempted to cut or jump the barriers, but they were called out by others in line. Wiener said it felt like at any moment the line would fall apart and people would start rushing the entrance. It was a "fiasco," he said.

"We all wait in lines, but not like this. It took two hours for us just to give our tickets in," he said. "Deadheads are a pretty mellow bunch, but I'd hate to see it if this were a heavy metal band and this kind of thing happened."

Some concert-goers stuck in line took to Twitter to describe the situation, begging Dead & Company to hold off on starting the show. The band came on stage about 45 minutes late, but even then there were still "thousands" of people stuck outside, according to attendees. By the time Wiener and his group took their seats, they had missed about four of the band's famously drawn-out songs.

"I've been to a lot of shows, and this was the worst logistical situation that I've ever seen," said Sean Comey, a Mountain View resident who was also stuck in the line. "It was so frustrating because you could hear the band come out, and there were still thousands of people waiting to get in."

An estimated 40,000 people attended the Dead & Company's two-night appearance at Shoreline Amphitheatre, which kicked off the venue's summer concert season. Lawn tickets for the event sold for just under $50, not counting retail surcharges. Comey said he and his group had paid about $250 per ticket for their seats.

Concert-goers say a slow security checkpoint was to blame for long wait to get inside the venue. The checkpoint, which involved about six metal detectors and mandatory bag checks, looked to be understaffed with only one person checking items per line. In some cases, it seemed to take security guards more than a minute just to inspect one bag, several attendees said. The security checkpoint wasn't a problem for the Friday, May 31, show, but it seemed especially slow for the Saturday concert.

Live Nation spokeswoman Liz Sharkey said in a statement to the Voice that the "vast majority" of fans entered the show without any major problems. She apologized to those who had to wait a long time to enter.

"We do our best to manage lines in an efficient and safe manner, and we're always assessing how to improve," she said. "We encourage fans to plan to arrive early and subscribe to venue communications for updates for the most seamless entry experience."

The grueling wait is still a sore subject for some Grateful Dead fans. Fans on Twitter pledged to never attend another concert at Shoreline. Wiener said he sent Live Nation an angry letter co-signed by an attorney to lay out his grievances.

"I was so upset that this organization was so ridiculous. Now I just want them to know the severity of how badly they screwed up," he said.