Tucson, Arizona:

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.

Please answer a question about this article. If the question is unanswerable, say "unanswerable". How many miles is Catalina Highway?
25