Ski mountaineering made its Olympic debut on Thursday. For fans and competitors alike, it was a day to remember.

Ski mountaineering tests strength and endurance as athletes race uphill on skis and on foot before going back down.

Ski mountaineering, or “skimo,” is the first entirely new sport at the Winter Olympics since 2002. As its name suggests, skimo combines elements of skiing and mountaineering, requiring competitors to ...