Welcome to OS Omaha 2025 Welcome to OS Omaha, the model railroad invitational operating weekend in Omaha, Nebraska. Our 2025 weekend is scheduled for Friday, October 24th through Sunday, October 26th. 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 2025.