Welcome to OS Omaha 2023 Welcome to OS Omaha, the model railroad invitational operating weekend in Omaha, Nebraska. Our 2023 weekend is scheduled for Friday, October 20th through Sunday, October 22nd. With 18 layouts planning to operate, this promises to be one of the largest OSOmaha events ever and a fun weekend for all of our out-of-town guests. We look forward to seeing you here in Omaha in 2023.