Yoga helps regular hikers become more limber, mindful, and aligned when they hike. And hiking offers greater lung capacity and overall-fitness to yogis who tend to do a less mat practice.
Doing yoga on unfamiliar turf (literally) brings other benefits. The unfamiliarity makes the experience rich.
Learning to stay focused enough to practice yoga outside the studio amid distractions like noise and weather, is good training for staying attentive and flexible off the mat.