The Big Tree Trail is a popular trail in the Oregon Caves National Monument. The trail begins at an archway behind the visitor center and if you complete the full loop, it is just over 3 miles, with 1,100 feet of elevation gain. This section of the Big Tree Trail is where most of the elevation is gained; you switchback up a steep climb through mountain meadows, dense forests, and past the widest Douglas fir tree known in Oregon! You also take the Big Tree Trail if climbing up to Mount Elijah, one of the longer and more challenging hikes in the area.