Omaha Costco Marathon

Omaha Costco Marathon takes place in Omaha, Nebraska, on December 12, 2026. The marathon (26.2 miles) starts at 7 a.m. and is the only distance on the program, so there is one start line, one field and one finish to aim at. With no shorter option to drop down to, everybody standing on that line on race morning is going the full way.

The distance sets the terms. A December marathon puts the bulk of the work in the fall: sixteen to eighteen weeks of steady mileage, a weekly long run climbing toward 18 or 20 miles, and a handful of sessions at goal pace so the rhythm feels familiar when it counts. If it is your first, plan a conservative opening half and treat the last 10K as the real race. If you are chasing a qualifying time, know your splits before the gun and hold them through halfway rather than banking time early.