Ilani Casino Resort, along Interstate 5 west of La Center, began erecting its sign on Friday. A big economic splash is expected when it opens in mid-April with more than 1,000 employees and 15 as-yet-unrevealed restaurants, shops and bars. The casino, at 368,000 square feet, reportedly cost $510 million. It is jointly developed by the Cowlitz Tribe and Mohegan Tribe of Indians of Connecticut.