In this task, you are given a question and a context passage. You have to answer the question based on the given passage.

What is a popular activity along Catalina Highway that involves riding a single sliding object down a snowy slope?, Context: Catalina Highway stretches 25 miles (40 km) and the entire mountain range is one of Tucson's most popular vacation spots for cycling, hiking, rock climbing, camping, birding, and wintertime snowboarding and skiing. Near the top of Mt. Lemmon is the town of Summerhaven. In Summerhaven, visitors will find log houses and cabins, a general store, and various shops, as well as numerous hiking trails. Near Summerhaven is the road to Ski Valley which hosts a ski lift, several runs, a giftshop, and nearby restaurant.
snowboarding