The 100-km (62-mile) race began on Saturday (May 22) from a scenic area at a bend in the Yellow River known for its sheer cliffs and rock columns. The route would take runners through canyons and hills on an arid plateau at an elevation of over 1,000 meters (3,300 feet).
The race kicked off 9 a.m. (0100 GMT) with runners clad in t-shirts and shorts under overcast skies, according to photographs posted on the social media account of the Yellow River Stone Forest area in Jingtai, a county under the jurisdiction of Baiyin city.
Around noon on Saturday, a mountainous section of the race was hit by hail, freezing rain and gales that caused temperatures to plummet, officials from Baiyin told a news briefing on Sunday (May 23).
A massive rescue effort was initiated, with over 1,200 rescuers dispatched, assisted by thermal-imaging drones, radar detectors and demolition equipment, according to state media.