Robbie Harrison is a Santa Rosa building inspector and a veteran Deadhead who has attended rock festivals all over the world.

On Thursday, the Forestville man relaxed outside his tent in what may be the most unusual setting of all his rock-and-roll adventures, a park in Napa where hundreds are camping out this week for BottleRock.

"This could work out really well," said Harrison. "It's mellow. So far."

The campsite breaks new ground for Napa, where tents normally are reserved for wine club members and camping out is a term usually applied to waiting for a good seat at one of the city's much smaller special events, such as an annual holiday parade.

By contrast, the temporary tent city at Skyline Park about two miles from where BottleRock is being staged has attracted music fans from around the world, including Mark Andrews and two of his friends who arrived in Napa on Wednesday after driving 15 hours from British Columbia.

Andrews, a telecom worker, soaked in the rays of a warm sun while seated in a folding chair with his shirt off. He and his friends, who are in their 30s, have never been to California before. They spent $599 each on four-day VIP passes to BottleRock, in what they said amounted to a trip of a lifetime.

"Awesome lineup. California. It's definitely a bucket-list kind of thing," Andrews said.

With every room booked in the Napa Valley and in many surrounding communities for BottleRock, camping became the only option for die-hards who want to stay overnight near the event.

As many as 1,800 campers are expected to take over the vacant field at Skyline, which is owned by the state of California. The camp was about half-full Thursday but is expected to be packed this weekend, with all 450 campsites taken.

The campsite on Thursday included the usual rock-and-roll requisites of tie-dye and aroma of marijuana. But it also had a laid-back Wine Country vibe appropriate for the setting.

Several campers said they chose to attend BottleRock over other festivals that can attract a hard-core clientele. The scheduled acts for BottleRock range from hip-hop sensations Macklemore and Ryan Lewis, who performed Wednesday night, to baby-boomer stalwarts such as Jackson Browne.

Noah Hale, a construction worker who flew in for the event from Maui, said he chose BottleRock because he felt the event would be "more about the music and not balls-out partying."

He's staying at the campsite in Napa with several friends who drove 16 hours from Big Sky, Montana to attend the rock festival. Said Casey Folley, an employee at a ski resort, "I'm more into this because it's a first-time festival. Maybe I'll buy a shirt."

Individual camp sites cost $80 a night over the weekend, a steal compared with the cost of hotel rooms and other lodging options in the Napa Valley.

On Thursday, private security and Napa County sheriff's deputies cruised the site. A fire truck from a county fire agency also was on hand.

"We're just trying to keep everybody safe," said Greg Lyons, owner of Safe Camp Red Rock. He said he formed the limited liability corporation and entered into a contract with the state to operate the campsite.

Campers are being shuttled to and from the expo in buses. The hardier among them are riding bicycles.

"So far this is beautiful," said Kristen Quinones of Los Angeles, who attended this year's Coachella festival in Indio, near Palm Springs, and still wore a wristband from that event. "You have a wide variety of things to do here. We even brought our kite."

(You can reach Staff Writer Derek Moore at 521-5336 or derek.moore@pressdemocrat.com. On Twitter @deadlinederek.)