Cowlitz Indian Reservation — Ilani Casino Resort, the $510 million casino that took over a decade to bring to reality, is here.The casino opened at 10 a.m. Monday with a ribbon-cutting and ceremony. After the event at the casino, at Exit 16 of Interstate 5 near La Center, the casino is open seemingly for good — 24 hours a day, seven days a week.Traffic was backed up nearly a mile on Interstate 5 as of 10 a.m. from Exit 16.Behind the doors of Ilani — pronounced ay-lah-nay, the Cowlitz word for “sing” — lie 2,500 slot machines, 75 card tables and a handful of restaurants and shops. Slots range from penny slots to $5 denominations.The game floor encompasses 100,000 square feet. One-third of the floor is set aside for non-smokers, and casino officials boast of its high-tech ventilation system designed to keep the air clean. The casino’s gaming floor is restricted to guests ages 21 and older.There will be more than 3,000 parking spaces to handle the expected deluge of visitors. Some projections say the casino can expect 4.5 million visitors annually. There is no lodging on the reservation, but officials expect to build a 400-room hotel in the coming years.Free concerts will be held every night for the first week, today through Sunday. British glam rockers The Sweet, famous for the song, “Ballroom Blitz,” will kick off the concerts today. The concerts will be held at the casino’s in-house entertainment lounge, Muze.