The best thing about hiking and wildlife watching in Yellowstone is that people of all ages and abilities can participate. On easier hikes, you’ll cross gentle and mostly flat terrain with minimal elevation gain. Intermediate hikes will see a little more change in elevation (up to 700 feet) and the trails include sections of rocky terrain and other obstacles. Moderately strenuous hikes have uneven rocky terrain and other obstacles with up to 1,000 ft of elevation gain. On advanced hikes, you’ll encounter steeper, rocky terrain, possibly off-trail, with steep inclines and possibly over 1,000 ft in elevation gain. The minimum starting elevation is about 6,000 ft above sea level and you’ll go up from there. Keep in mind, the weather in the summer can be very hot and you’ll also be packing a daypack filled with water and other things you’ll need throughout the day.
For wildlife watching, you won’t need to stray too far from the vehicle as wildlife watching is most effective from the road (with short walks to vantage points, up to about a half-mile each). Daily departures are at dawn (5 to 6 am in the summer, 7 am in the winter) and the duration of the tour is typically 7 to 8 hours.