I sometimes crossed range land (usually on the Wolf route) where I hiked toward a landmark or a fence corner. Once a fire closure put me on a confusing system of unmapped logging roads, and it was easier to hike off trail up to treeline to get back on the Divide.
The CDT offers options to purposely travel off trail. On an exceptional day above treeline, you may choose to take a high ridge route rather than the mapped route down in the valley below.
Sometimes the trail is so faint or (snow-covered) where it enters the trees, some orienteering is helpful.
All the XC travel I remember was with good views and it was easy to stay oriented on the map as long as you paid attention. It was seldom necessary to take a bearing, but once or twice it was a good skill to have.