Task: Question Generation
Input (English): Passage: Most park visitors sightsee using the scenic drive, which provides access to 13 viewpoints over the amphitheaters. Bryce Canyon has eight marked and maintained hiking trails that can be hiked in less than a day (round trip time, trailhead): Mossy Cave (one hour, State Route 12 northwest of Tropic), Rim Trail (5–6 hours, anywhere on rim), Bristlecone Loop (one hour, Rainbow Point), and Queens Garden (1–2 hours, Sunrise Point) are easy to moderate hikes. Navajo Loop (1–2 hours, Sunset Point) and Tower Bridge (2–3 hours, north of Sunrise Point) are moderate hikes. Fairyland Loop (4–5 hours, Fairyland Point) and Peekaboo Loop (3–4 hours, Bryce Point) are strenuous hikes. Several of these trails intersect, allowing hikers to combine routes for more challenging hikes.
The park also has two trails designated for overnight hiking: the 9-mile (14 km) Riggs Spring Loop Trail and the 23-mile (37 km) Under-the-Rim Trail. Both require a backcountry camping permit. In total there are 50 miles (80 km) of trails in the park.
More than 10 miles (16 km) of marked but ungroomed skiing trails are available off of Fairyland, Paria, and Rim trails in the park. Twenty miles (32 km) of connecting groomed ski trails are in nearby Dixie National Forest and Ruby's Inn.
The air in the area is so clear that on most days from Yovimpa and Rainbow points, Navajo Mountain and the Kaibab Plateau can be seen 90 miles (140 km) away in Arizona. On extremely clear days, the Black Mesas of eastern Arizona and western New Mexico can be seen some 160 miles (260 km) away.The park also has a 7.4 magnitude night sky, making it one of the darkest in North America. Stargazers can, therefore, see 7,500 stars with the naked eye, while in most places fewer than 2,000 can be seen due to light pollution, and in many large cities only a few dozen can be seen. Park rangers host public stargazing events and evening programs on astronomy, nocturnal animals, and night sky protection. The Bryce Canyon Astronomy Festival, typically held in June, attracts thousands of visitors. In honor of this astronomy festival, Asteroid 49272 was named after the national park.There are two campgrounds in the park, North Campground and Sunset Campground. Loop A in North Campground is open year-round. Additional loops and Sunset Campground are open from late spring to early autumn. The 114-room Bryce Canyon Lodge is another way to stay overnight in the park.
Output (English): Which of the moderate hiking trails is estimated to be longer?