Leave Jackson Hole around 7:00 AM after fueling up; this is a long, scenic day, and an early start gives you the best chance of avoiding wildlife backups and Yellowstone congestion. Follow US-191 north through the Grand Teton–Yellowstone corridor, entering Yellowstone at West Thumb and continuing toward Old Faithful. Plan on roughly 4½–5½ hours of driving time before stops, but allow extra time for construction, roadwork, animals, and slow traffic. Check Yellowstone road conditions before departure, carry food and water, and remember that cell service is unreliable. At Old Faithful, allow about 1½ hours for the eruption—visitor-center predictions are usually posted shortly before the event—and walk the nearby Upper Geyser Basin boardwalks. The area has large parking lots, but they fill quickly in summer; expect a small entrance fee unless you have a national parks pass.
From Old Faithful, continue north through Yellowstone toward Mammoth Hot Springs; the drive is scenic but can take several hours with park traffic, so keep the stop focused. Spend about an hour on the Mammoth Hot Springs terraces, using the boardwalks and drive-up viewpoints to see the white, orange, and ochre travertine formations. Stay on designated paths—the terraces are hot and fragile—and watch for elk around the historic buildings. Then eat at Mammoth Dining Room, a convenient sit-down option near the terraces; budget approximately $20–35 per person, and check the current seasonal schedule because Yellowstone dining hours can change. If it is busy, the nearby Mammoth Hot Springs Hotel area is also useful for restrooms and a short break.
After leaving Yellowstone through the north entrance, continue via US-89 and US-191 toward Bozeman, checking in or parking near historic downtown before strolling Main Street. The downtown core is compact and easy to explore on foot, with independent shops, galleries, and cafés; after a long drive, one relaxed hour is plenty. If you are genuinely rested and road conditions are clear, the planned return to Jackson Hole via US-191 takes about five hours, making a 6:00 PM departure a very late arrival—verify Yellowstone access, daylight, weather, and fuel before committing. In practical terms, staying overnight in Bozeman is the safer choice after this full sightseeing day; if returning, fuel before leaving town and expect limited services along the route.