LAS VEGAS — A country music extravaganza featuring some of the biggest names in the genre will descend on Las Vegas this fall, taking a cue from the massive rock, pop, electronic dance music and indie festivals that have recently made Sin City home.Concert producer Live Nation and casino company MGM Resorts International announced Thursday that they're collaborating on the inaugural, three-day Route 91 Harvest festival, set to take place Oct. 3-5 in an empty lot near the Mandalay Bay resort."We're not kidding around. We have to go for it," said Brian O'Connell, president of Live Nation's country touring division and producer of similar festivals in Washington state and Michigan. "In order for us to stand up and be noticed (in Las Vegas), we have to put together a spectacular show."The event, which uses the historical name of present-day Las Vegas Boulevard, will include country A-listers Jason Aldean, Miranda Lambert, Blake Shelton, Dierks Bentley and Brantley Gilbert. Others on the roster include Dwight Yoakam, Randy Houser and Dustin Lynch.Three-day passes start at $169 and go on sale Aug. 1.The event is the latest large festival to launch in or move to Las Vegas in recent years. The city is already host of the Electric Daisy Carnival rave in June, the Life is Beautiful festival in downtown Las Vegas in late October, and the iHeartRadio Music Festival, produced by radio giant Clear Channel in September.The inaugural Rock in Rio USA event, modeled after a mega-festival launched in Brazil, is scheduled for May 2015.O'Connell said he couldn't guess how many people will attend the first Route 91 Harvest festival, but hopes it will become an annual affair running for decades to come."I'm not in this for the short run," he said.