When Shane Bottens decided to put together a music festival celebrating all things metal, he had a very specific vision in mind.

"I always wanted to try my hand at the open air festival," he says. "It's kind of a niche thing and there's nothing around that fits the bill."

Having performed in bands at several open air metal festivals in Europe, Bottens decided to run with the idea, throwing the first iteration of the event last September. The Pekins, Illinois, native enlisted 75 bands to perform on three different stages at Cave-In Rock State Park in Illinois, some three hours from St. Louis. He dubbed it "Full Terror Assault: America's First 'True' Open Air Festival." Metalheads could camp, imbibe and enjoy an atmosphere free of security guards.

Though well-received, it was a learning experience for Bottens, who works tirelessly to maintain an ethic about open air festivals.

"To me, if you're going to call yourself open air, you've got to have some national acts and a great facility," he explains. "You can't throw some generators up in a field and call it open air. It's gotta be legit."

The term can be elusive. Many festivals claim they are "open air." But Bottens says don't be fooled — those are just outdoor concerts.

"In Europe, the summer festival scene is huge: Wacken Open Air, Hell Fest — but over here, if you have shows outside, it's not really a true open air fest, where you're actually camping," he says. "When you do that for a few days, you become part of a little community. You don't see a lot of that here, especially for extreme music.

"For the underground/grindcore/death metal/punk scene," he continues, "there's nothing like Full Terror Assault in the United States."

This month, the Full Terror Assault Open Air Festival is back for a second go-round, with a slimmer lineup of 55 bands on two adjacent stages. There will be no shortage of talent, including St. Louis heavy-hitters Thorhammer, Fister and the Lion's Daughter — a proper soundtrack for a gore-porn snuff film or car crash fetish website. Bottens is proud of the work that's gone into this year's line-up. "There are a lot of great bands playing from the top to the bottom — there's not a filler in the bunch."

Cost of admission for the two-day event includes camping and a mix of some of the best death metal, grindcore, hardcore, punk and metal in the country, because, let's face it, the last thing you want to do is watch 50 grindcore bands in a row.

That's another characteristic Bottens is trying to recreate from the European open air festivals — variety. He's even managed to gain the attention of classic thrash metal band Sacred Reich, who released a series of records in the '80s and '90s and reformed in 2007 to perform the open air circuit in Europe. Bottens made a plea for them to come to his festival, and the band heeded his call.

"He's trying to establish a real open air U.S. metal festival," says Sacred Reich bassist Phil Rind. "Our favorite memories are playing these small metal festivals that started out with a couple thousand people and grew to a hundred thousand people over time. So everyone has to start somewhere, and we're happy to be a part of that."

Sacred Reich has been playing all over Europe and has grown enamored of the music scene there, rarely playing the States, but Rind has high hopes for Botton's endeavor.

"A lot of these things you see lately are big corporate festivals. It's not what we're familiar with in Europe, with something that's grown organically," he says. "And Shane seemed real earnest and honest so we said 'Yes, let's do it. This is who we are, let's be a part of it.'"

And for Bottens, his dream of growing the festival seems to be taking off.

"The more people I get involved, then the bigger-name bands I can get, and this thing will really start to grow," he says.

What would be a bigger name band? "I'd love to get Slayer there, man," he laughs. But rest assured — he's not kidding. Though he's excited for this year's festival, he knows there's a lot more work to do.

"When you've got to build something, like a band or a festival, it takes time to do that," he says. "If it were easy, everybody would be doing it, but it's not an easy thing to pull off."

Ticket sales have nearly doubled from last year, but because of the expansive campgrounds, there's no danger of selling out just yet. Bottens admits it would be great to get to that point in the future, as the campground could conceivably hold 15,000 people. And that would mean he's doing something right.

"If I didn't believe it, I wouldn't keep doing it," he says. "I think it's going to be massive in the years to come."