Today we hike south of Gibbon Meadows to Monument Geyser Basin, one of the strangest spots in the park. The small, nearly dormant basin lies at the top of a very steep one-mile trail. Thermos-bottle shaped geyser cones are remnants of a much more active time. The “monuments” are made of siliceous sinter and appear very similar to the siliceous spires found on the floor of Yellowstone Lake. Scientists think that this basin’s structures formed from a hydrothermal system in a glacially dammed lake during the last stages of the Pinedale Glaciation.

     This trail meanders along a gentle gradient following the Gibbon River then it turns sharply uphill and climbs 500 feet in 1/2 mile to the top of the mountain! Footing is on eroding geyserite and rhyolite, somewhat reminiscent of ball bearings. The geyser basin is a very interesting collection of geyser cones of varying sizes.

     Unfortunately, all but one of these geysers are now dormant, having sealed themselves up. Thermos Bottle Geyser still steams and sprays a little water standing proud at 10' tall.

     Incredible views and the smell of sulfer let us know we are near the basin. To the north, Gibbon Meadows stretch out, the wide meanders of the river clearly visible from this vantage point. Beyond the basin to the northwest rises the Gallatin Mountain Range, with Mount Holmes quite prominent. The Washburn Range comprises the mountainous terrain in the far distance to the northwest. Directly below is the Gibbon River Canyon. Past this canyon layers of lava flows stretch out to form the Yellowstone Plateau.

     Although the hike was tough, we enjoyed exploring nature's own sculpture garden.