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2010 Trip Report - Mono Basin

Mono Basin and Ichthyosaur State Park
June 18 - 20 2010
By Allan Schoenherr

Imagine the confusion!!! The meeting place for this trip, the rest stop on  Highway 395, was closed for repairs. Some last minute e-mails succeeded in  communicating a change for the Friday morning meeting to the intersection of  Highway 395 and the Mammoth Lakes Scenic Loop (The earthquake escape route). An  added frustration appeared on Thursday evening when it was discovered that the  proposed campsite at Lower Deadman Campground was closed due to flooding.  Undaunted, we selected a scenic spot in the forest along the Mammoth Lakes  Scenic Loop.

Friday morning: Five cars left from the appointed meeting spot and traveled to  the southernmost of the Mono Craters, which are aptly named Inyo Craters, as  they lie in Inyo County, just off the Scenic Loop. Participants included Mignon  Slentz, Glenn Shaw, George Gilster, Sally Kinsey, Robert Day, and Steve Miller.  A short, but semi-steep hike, through a shady Jeffrey Pine forest, brought us to  the two craters. These side-by-side craters, were caused by volcanic steam  explosions about 600 years ago. What makes these twin craters especially  interesting is that they have lakes in the bottom which are entirely different  in color. One lake is a murky green and the other is a clear blue. Some  references say the cause of the differentt colors is unknown, but a recent  scientific paper explains that different chemistry is responsible for the  colors. The clear lake has more of a forest margin which adds organic material  to the water. Decomposition of the organic material makes the lake slightly  acidic which causes precipitation of suspended material so that the water  remains relatively clear and blue. The other lake with all its suspended  material remains green and cloudy. Experimental addition of sulphuric acid to  the cloudy lake caused it to become temporarily clear.

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Next stop was Obsidian Dome, a scenic jumble of huge obsidian boulders. A number  of these domes, composed of obsidian or pumice, lie along a fault line that runs  from Mammoth Mountain to Mono Lake. They are conspicuous from the air, but can  be seen from Highway 395. We talked about how obsidian is formed, how to  identify the different kinds of pine trees, and we stopped here for lunch.

After lunch, following a quick stop for fuel at the June Lake junction, we  headed toward Mono Lake. Just south of Mono Lake there is a conspicuous row of  volcanic hills known as Mono Craters. From an age of 10,000 to 2,000 years,  these craters continued to erupt until about 600 years ago, which makes this arc  of 27 craters the youngest mountain range in the United States. One of the  northernmost of these craters is Panum Crater. This crater originally was formed  by a gas explosion similarly to the Inyo Craters. However, a second eruption  produced a large plug of picturesque obsidian in its center. A steep trail leads  up to the plug and everyone in our group made it to the top in order to marvel  at the spectacular views of the eastern Sierra Nevada, Mono Craters, and Mono  Lake.

Next, we stopped at South Tufa on the shoreline of Mono Lake. Mono Lake is a  very concentrated saline lake, a consequence of its great age. The lake may have  continuously held water for 2 million years, during which time the evaporation  of water has left behind an accumulation of dissolved minerals. The picturesque  tufa towers are pinnacles of calcium carbonate which were produced by  precipitation under water, a process caused by the bubbling of fresh water  through the brine. In 1942 the Los Angeles Department of Water and Power began  diverting the fresh water streams that fed Mono Lake southward into the LA  Aqueduct. Ultimately, with reduced fresh water input, the lake level was lowered  by 40 feet, exposing the tufa towers. The area is now classified as a National  Scenic Area. During the period of lowest water an island in the center of the  lake became connected to the shoreline. For thousands of years, this island has  been one of the most important nesting areas for the California Gull. The  lowered water level enabled coyotes to travel out to the island and prey upon  the nests of the gulls, seriously threatening survival of the species. Today, in  an attempt to bring back the lake level to a more normal height, the Department  of Water and Power is required to allow a portion of the fresh water to  continuously flow into the lake. The simple ecosystem of Mono Lake depends on  high concentrations of Cyanobacteria (Blue-green Algae) that thrive in the  hypersaline water. Brine Shrimp and Brine Flies eat the algae. The Brine Flies,  conspicuous at the water’s edge, lay their eggs along the shoreline. The birds  eat the Brine Shrimp and the Brine Flies. Indians formerly ate all of them,  including a food made from the Brine Fly eggs. During our visit, the wind was  blowing the Brine Flies off the shore onto the water. We were able to watch the  gulls, positioned into the wind, floating on the water while they gorged on the  flies.

Friday night we set up camp in a grove of Pinyon and Jeffrey Pines on the south  side of Mono Lake. We had a spectacular view of the lake as we enjoyed our  traditional potluck. We were joined at that time by Leonard and Rebecca  Friedman, and their daughter Hannah, who entertained us with word games in the  evening as we sat around the campfire.

Saturday’s activities began at the Mono Lake Visitor Center. Then our group of  six autos traveled by dirt road up scenic Cottonwood Canyon to the famous ghost  town of Bodie. We spent the morning looking around and photographing the  interesting restored and preserved buildings. We ate lunch in a day-use site  just east of the town. After lunch, we ventured into unknown territory as we  followed a dirt road eastward along Bodie Creek toward the ghost town of Aurora  and ultimately Hawthorne, Nevada. We were warned the road would be rough, and it  was, but it did not phase the Desert Explorers. First stop was an old stamp  mill, but we stopped many times as we enjoyed the canyon scenery and the  wildflowers. We stopped for gas in Hawthorne and then moved on to the scenic  campground amongst the Pinyon Pines at Berlin-Ichthyosaur State Park. Park  personnel were waiting for us with descriptive pamphlets and signs directing us  to our reserved campsite. That evening we enjoyed another fine meal, a campfire,  and group comraderie.

The next morning we convinced the park ranger to do an early tour of the  Ichthyosaur site (the Nevada state fossil) and were treated to an enthusiastic  explanation of the significance of this spectacular fossil site. These ancient  extinct reptiles represented a life style now demonstrated by marine mammals  such as dolphins and whales. In fact the Ichthyosaurs at this site were among  the largest of their kind. Imagine 60-foot-long reptiles with mouths like  crocodiles, living a lifestyle like a modern day Moby Dick (Sperm Whale). We had  a group photo taken in front of a life-sized mural of an ichthyosaur. Not  realizing we had an early tour, Bob and Sally already had left for home and  unfortunately missed the photo. After our tour most of us wandered around the  restored ghost town of Berlin before traveling for home. Thereafter, some folks  went on to other destinations including the nearby ghost town of Ione. Tours of  the Berlin mine itself had been temporarily discontinued because of budget  cutbacks.