Starting from the U. S. Postal Service office in the community of Mammoth within YNP, continue south on the road toward Norris. Go about 3.5 miles to the Upper Terrace parking lot which, in winter, is blocked off into a dead end (the road beyond is closed from late November until late April). From the parking lot, it's an easy stroll on a wooden boardwalk out to the terrace area.
This image was taken in very late afternoon, shortly before sunset. The best light from this angle is just before dusk. Early morning light can also work well at this area for shooting different angles.
Upper Terraces at Mammoth Hot Springs, Yellowstone National Park (YNP), Wyoming.