The trailhead for the hike to Purple Mountain is 0.2 miles east of Madison Junction
, at a turnout on the south side of the highway, opposite an employee residence area. Guests at the nearby Madison Campground can reach the trail via a short connecting path behind the residence, joining the main route which starts next to a small meadow and leads northeast into dense woodland, remaining tree-bound all the way to the summit. The surroundings are overgrown, and undamaged by fire, so provide good cover for bears and other creatures of the forest. The narrow trail has a consistent uphill gradient without ever being particularly steep, climbing an undulating hillside crossed by many small gullies, some containing transient streams, until reaching a larger ravine filled with fallen tree trunks. The trail then turns back west and is quite straight for a while, enclosed by taller trees, until, about 2/3 of the way to the top, starts a series of long switchbacks, which finish as the route moves away from the edge of the mountain, up a valley to the plateau.
The Purple Mountain Trail ends with a level section back south to the edge of a promontory projecting out a little and giving a 180° view over the valleys 1,500 feet below; the best perspective is from a treeless area a short distance down the slope. On a clear day the panorama extends south across Madison Plateau towards the Tetons (50 miles), east to the Central Plateau and west to the mountains of the continental divide, in Idaho.