Length: 4-16 miles
Duration: 2-8 hours
Difficulty: Easy to moderate
Elevation Gain: 450 feet
Activities: Hiking, mountain biking, trail running
Crowds: Moderate traffic
The northwest corner of Yellowstone National Park along Hwy. 191 is littered with trailheads, and Specimen Creek is just one of many drainages lending itself to a pure, natural outdoor experience that is harder to find through all the riff-raff inside the Park's main entrances. Yes, it's a popular trail, and you're bound to encounter a few other visitors along the way, but you won't find boardwalks, hotels, gift shops, or anything of that sort. Just the mountains, trees, wildlife, and whatever company you bring along—which, it's worth noting, does not include dogs, as they are prohibited inside the Park boundaries.
The main branch of Specimen Creek Trail follows a broad, flat valley along its namesake creek before climbing steeply up to Shelf Lake; this entire route is about 16 miles out-and-back. Another option is to branch off after six miles toward Crescent Lake, which is reached after another 1.5 miles for a slightly shorter out-and-back. Or, for a shorter outing, you can hike up the valley as far as you please and turn around—the junction with Sportsman Lake Trail makes a good stopping point for a four-mile out-and-back.
This drainage is popular in winter for hikers, snowshoers, and Nordic skiers. The trail isn't groomed, so don't bring your skate skis, but it's usually packed down enough to use skinny classic skis or hike without snowshoes. Caution: The final climb to Shelf Lake is prone to avalanches in winter. There is also some awesome backcountry-skiing terrain in this drainage; we'll let you sniff it out for yourself.
Head south on Hwy. 191 past Big Sky. 4.5 miles after the sign for Yellowstone National Park, the Specimen Creek trailhead will be on your left. This parking lot is quite small, so have a backup plan in case it's full when you arrive—there are plenty of other options nearby.