The Koi Nation of Northern California has taken a major step toward advancing a large resort-casino project just outside Windsor, announcing a predevelopment agreement with the Chickasaw Nation of Oklahoma.

Under the agreement, Global Gaming Solutions — a wholly owned business of the Chickasaw tribe — would partner with the Koi on its planned Shiloh Casino & Resort. The company would also manage and operate the facility on East Shiloh Road in unincorporated Sonoma County. Koi leaders say the enterprise will include 2,500 Class III gaming machines, a 200-room hotel, six restaurants and food service areas, a meeting center and a spa. In all, the complex will employ more than 1,100 full-time workers when fully operational.