Jupiter Spring is situated just south of Minerva. It was named in the 1880’s because of its imposing and towering formation. Jupiter was a Roman god of the elements: the thunderbolt was his sign and the rainbow his messenger. If you listen quietly you may hear the hot water thundering down the terraces of this feature. The rainbow of algae covering its terraces is obvious. _AUTO TOUR OF THE UPPER TERRACE_ The entrance to the Mammoth Terrace Drive is one and one-half miles south of the Mammoth Visitor Center on the road to Norris. This scenic auto tour winds for one and one-half miles among several active thermal springs and has convenient parking pull-outs along the route where you can stop and become better acquainted with the features. The drive is a one-way loop road and due to several sharp turns it is necessary to exclude towing units, buses and motor homes in excess of 25 feet in length. Remember that thin crust and very hot water make caution especially important when you are near thermal features. [Illustration: _MAMMOTH HOT SPRINGS AREA Lower Terraces_] CANARY SPRING MAIN TERRACE NEW BLUE SPRING JUPITER TERRACE NAIAD SPRING MINERVA TERRACE RESERVOIR SPRING CAVERN SPRING DEVIL’S THUMB LIBERTY CAP OPAL TERRACE UPPER TERRACE DRIVE NORRIS AND UPPER TERRACE DRIVE MAMMOTH VILLAGE _LOWER TERRACE OVERLOOK_ This viewpoint offers an excellent overview of the springs and pools of the Lower Terraces. The large blue pool ahead and to the right is Canary Spring. The pools visible to the left are the New Blue Springs complex. The names of these features suggest colors which are inconsistent with what we see today. The color of both features has changed from when they were originally named. Changes in environmental conditions may account for this: perhaps a change in water temperature. The trail to the left goes around New Blue Spring and on down over the terraces to Minerva Spring. Near that point the trail branches to the right to Jupiter Spring and past Minerva itself, or left to Liberty Cap. Both routes lead to parking areas along the lower road. Beyond the terraces the red-roofed buildings on the right are those of historic Fort Yellowstone, built and occupied by the U.S. Cavalry during their tour of duty here from 1886 to 1918. The ecological community in this section of the upper terraces is worth noting. The high content of decayed travertine produces a porous soil which dries out quickly. Consequently, vegetation is sparse and is limited to those species which are tolerant of such conditions. Several variations may be seen in the plant communities at other points along the tour road. What environmental conditions can you detect that might be influencing these differences? _NEW HIGHLAND SPRING_