and Canadian lynx (Lynx canadensis) also live in the park but are seen less frequently. The willow ptarmigan (Lagopus lagopus), Alaska's state bird, as well as the rock ptarmigan (Lagopus muta) and white-tailed ptarmigan (Lagopus leucura) frequent alpine tundra and subalpine shrub thickets. Meadow voles (Microtus pennsylvanicus) by contrast live underground in alpine and tundra habitats. Hikers may hear the chirps of the singing voles (Microtus miurus). During fall, these rodents construct piles of grasses and plants near their burrows. Smaller mammals inhabiting this area include red foxes, porcupines, hares, ground squirrels, ermines, and pikas. Turnagain Arm The Seward Highway follows part of the southern edge of the park along Turnagain Arm. This stretch of highway is listed as a National Scenic Byway and is designated as an All-American Road. Along Seward Highway is park headquarters located at the Potter Section House State Historic Site which once served as an important worker camp for the Alaska Railroad. There are several viewpoints along the Seward Highway. One of the most visited is Beluga Point, at milemarker 110.5, named for the beluga whales (Delphinapterus leucas) that frequent the area. Another popular viewpoint along the Seward Highway is Windy Corner at milemarker 106 where Dall sheep (Ovis dalli) are often visible just up the hill. The McHugh Creek Day use area features hiking trails and picnic areas. The Bird Creek Campground is located south of Anchorage off the Seward Highway. As with all campgrounds in the park, each camping site boasts a wooded spot for recreation and relaxtion, a fire ring and picnic table, with potable water and latrines nearby. Park volunteers at campgrounds and elsewhere offer assistance and answer visitor questions. Firewood is often available nearby for a small fee. Though dirt bikes are prohibited, the Bird Valley Trail System is the only location in the park open to ATVs all year round. Turnagain Arm boasts the second highest tides in North America after the Bay of Fundy. These tides, which can reach , sometimes come in so quickly that they produce a wave known as a bore tide. Adventurous kayakers and surfers have taken to riding the tide as an extreme sport. Hikers should take care not to get stuck in the quicksand-like mudflats that otherwise make up the beaches along Turnagain Arm. The best place to see the Alaskan bore tide is along Seward Highway south of Anchorage, especially at