This blog post is longer than would be ideal, but I don’t see an easy way to split it up, so I ask your forbearance.
The last month has been pretty challenging. Since I last wrote, many areas we hoped to visit, such as most state and national parks, and some national wildlife refuges, have closed. Camping opportunities are now essentially limited to Bureau of Land Management (BLM) dispersed camping areas. Our last night in an actual campground was on March 15, and we have spent the last 18 nights on BLM land. While not exactly sheltering in place, we are camping in such remote areas that we rarely encounter any people. We shop for food about once every two weeks, taking great care to avoid close contact with anyone, and get takeout food about once a week, usually from a Subway store. We are fortunate in that we have been in areas with very low population densities and COVID-19 infection numbers, and we feel that we are at least as safe as if we were renting in an extended stay facility, as we do in El Paso in the winter.
A second problem for us has been that the weather has been colder than we expected in our target area, the Great Basin Desert, with the spring season arriving more slowly than anticipated. Looking at climate data, I think my original plans had us exploring this area too early, even for a typical year, and it looks like this year might be colder than average, making things even worse. Furthermore, the COVID-19 closures have exacerbated the problem by removing destinations from our itinerary, causing us to get ahead of schedule, thereby reaching more northerly latitudes and higher elevations sooner than planned. These factors have caused us to retreat south into the Mojave Desert twice, to wait for better weather conditions.
The last blog post left off in the northeastern corner of the Mojave Desert, in extreme southwestern Utah. From there we headed northwest into the Great Basin Desert. The Great Basin can be defined in several ways. Hydrographically, it is the portion of the interior West that does not drain into any ocean. Instead, its rivers run into very flat-bottomed valleys, called basins, in which the water collects into lakes that may be dry for part of the year or for many years at a time. Because the waters flowing into these basins dissolve minerals from the soils they pass through, the lakes that terminate rivers accumulate high concentrations of salt and alkali materials, which precipitate as the lakes dry out. The result is a playa, which is a very flat, usually-dry lakebed, often encrusted with salts. The Great Basin, then, contains many smaller basins (around 75 of them), as well as the higher lands they drain.
The Great Basin is part of the geologically defined Basin and Range Province. This region is characterized by block faulting, in which the earth’s surface is stretched by tectonic forces, causing many parallel faults to form, perpendicular to the direction of the spreading. The long, narrow, parallel slices of land so produced can either subside, becoming valleys (basins), or be uplifted, sometimes with tilting, to become mountains (ranges). In the Great Basin, the stretching was in an east-west direction, so the roughly 175 named mountain ranges and their inter-mountain valleys run north-south. Consequently, when driving across the Great Basin going east or west, for example on famous Route 50 in Nevada (“America’s Loneliest Road”), there is a constant repetition of climbing up a mountain range, descending down it, and crossing a valley to the next range.
Mostly coinciding with the Great Basin, as defined hydrographically, there is an area defined instead by biological factors, called the Great Basin Desert. It occupies all of Nevada except the southern tip (which is Mojave Desert) and a small area around Reno. It also includes some adjacent portions of bordering states: most of the western third of Utah; southern Idaho; southeastern Oregon; and small areas in far eastern California, most notably around Mono Lake. Unlike the “cold” Great Basin Desert, the other three major deserts in North America (Mojave, Sonoran, and Chihuahuan) are considered “hot” deserts, with the flora being largely derived from subtropical sources.
Our first Great Basin Desert site was Cathedral Gorge State Park (SP) in Nevada. This small park has beautiful badlands scenery and impressive slot canyons cut through soft clay. We spent a couple of nights there and did a nice day hike on the Juniper Draw Loop, finding a species of Yucca (Y. harrimaniae) new to us. But it was so cold that we paid extra to hook up to shore power to run an electric heater, rather than deplete our propane. Looking at the long-range forecast for the next week, truly frigid conditions were expected, with rain and snow, so we decided to abort and return to the Mojave Desert, selecting Death Valley National Park (NP) as our destination. It would be two weeks before we made it back to the Great Basin Desert.
In Death Valley NP, we visited a number of favorite areas in the northern and western parts of the park, hardly overlapping with our short visit earlier in the year. We entered the park via Titus Canyon Road, a one-way four-wheel-drive dirt road that has marvelous scenery and fantastic botanizing. We paid homage to some of our favorite plants along the way, including: Holmgrenanthe petrophila, with only a few hundred plants known in the world, all in this canyon and nearby Fall Canyon; Eriogonum intrafractum, restricted to Death Valley NP, with a flowering stalk that breaks into many segments shaped like napkin rings; and Salvia funerea, likewise found only in Death Valley NP, a shrub with lovely purple flowers in spring.
The highlight of our time in Death Valley NP was visiting The Racetrack. It’s a long drive on a dirt road with legendary washboard corrugation; despite driving at a crawl we had a can of soda explode from the vibration, making quite a mess. But the final objective is truly compelling. The Racetrack is an oval-shaped playa about three miles by two miles, that occasionally becomes covered in water, usually in winter. At the south end of the playa, it was observed at least as early as the 1940s that heavy rocks, up to 700 pounds in weight, left skid marks that could stretch for up to 1500 feet! The trails left by different rocks typically were parallel, and the events leading to these remarkable tracks were clearly rare, as new sets of tracks might only be seen once per decade or so. Many theories were proposed to explain the movement, but the mystery was not solved until 2013, as detailed in a marvelous paper by Norris et al. in PLOS ONE (link).
What this team documented, with the help of rocks sporting GPS units to measure position, is that the rocks are moved by thin but large ice sheets in very modest winds. The rare sequence of events required is as follows. A winter rain storm deposits enough water to soften the mud floor of the playa and make it slippery, and to leave few inches of water on the surface. Overnight freezing creates a thin ice sheet (3 – 8 mm thick). Subsequent daytime warming by the sun causes the ice to crack into large plates (initially tens of meters across). These large, thin sheets are then moved by moderate winds (on the order of 10 miles per hour) and the water currents the winds produce. The ice sheet edges catch on the sides of rocks, which they then push across the flooded playa, at speeds up to twenty feet per minute!
We were thrilled to be able to see and photograph a number of clear rock trails in the concrete-hard cracked mud surface of the playa when we visited! We were especially fortunate as it snowed the next day, and it is illegal to walk on the playa unless it is bone-dry. While in this part of the park, we hiked around Ubehebe Crater, a marvelous walk with a nice selection of plants in bloom, including Purple Mat (Nama demissum var. covillei), a small annual plant that is so numerous on the dark cinder substrate that its flowers color whole swaths of the landscape magenta. A particularly exciting find for us near our dispersed campsite was Sibara deserti, an inconspicuous native mustard in a genus we had seen only once before. Our former record resulted from tracking down a site discovered by another botanist, so it was great to find it completely on our own.
After topping off the gas tank and learning that organized campgrounds in the park had just been closed, we headed for the spectacular Eureka Dunes area at the very northern end of the park. We spent one day hiking in nearby Dedeckera Canyon, a fantastic botanical site. It is named after the monotypic genus Dedeckera, found only in a few mountain ranges in the Death Valley region and just a short distance to the north. This rare lime-green shrub with yellow flowers blooms in mid-summer, when little else is flowering, and is known as July Gold. On our hike we photographed a fancy new butterfly, Sagebrush Checkerspot.
We exited from Death Valley N. P. to shop in the town of Bishop, then re-entered the park from the west, camping near Panamint Dunes for four nights. A day hike to these fairly remote dunes was very enjoyable, and despite our having over 300 records of plants from Death Valley prior to this year, we found two new plant species there, Lupinus shockleyi and Johnstonella costata. We also visited nearby Darwin Falls, involving a nice walk through a narrow riparian area before reaching the 20-foot Lower Falls, which had a decent amount of water flowing over them.
Leaving Death Valley NP (which soon thereafter closed completely to all visitation), we stopped in Pahrump, NV, a nice town for provisioning, where we shopped and filled up on drinking water and propane. Rumor had it that showing up at Walmart early in the morning, and standing in line for the opening, would provide a chance to obtain anti-bacterial wipes and toilet paper. We camped nearby and did just this, scoring these badly needed supplies for the first time since we have been on the road. We then headed back into the Great Basin Desert, where our first destination was infrequently-visited Basin and Range National Monument, in east-central Nevada. We made a large loop through the national monument, going in through Murphy Gap, and returning via, and camping at, Water Gap. The latter had some nice botanizing on dry limestone and was the most interesting area we saw.
Next on the agenda was Kershaw-Ryan SP. Nevada allowed day use of state parks, but no camping, so we stayed on nearby BLM land. We saw only one couple and one maintenance worker the entire day we spent in the park. We did a lovely loop hike, returning via the bottom of the gorge, where we were surprised to encounter several singing Black-chinned Sparrows at the northern edge of their range. We also added Red-naped Sapsucker to the year list. We again stayed on BLM land to visit rather remote Beaver Dam SP, where we saw only one vehicle, which was lost. On the drive back to civilization we tried a more dubious route than we used coming in, and were rewarded with Pinyon Jays and a fine herd of feral horses. However, we ended up being unable to reach a paved road without a farmer unlocking a couple gates for us and letting us go through his land.
We next crossed over into west-central Utah, heading for Fish Springs National Wildlife Refuge (NWR), which is located in the enormous Bonneville Basin. This basin was once filled with a lake up to a thousand feet deep, the remnant of which is the Great Salt Lake. On the drive in we saw Great Basin Ground Squirrel (Urocitellus mollis), which is well-named, as its range coincides so perfectly with the Great Basin Desert that you could define the desert by the squirrel’s distribution. From our campsite on BLM land lying along the Pony Express route, we identified three new species of shrubs all in the genus Tetradymia, a sort of botanical trifecta. Birding on the refuge was fair, our best bird being American Bittern, but the area seemed to have excellent potential.
We spent a day looking for crystals on the Topaz Mountain Adventures property, a mining claim within a larger rhyolite amphitheater on BLM land. Although topaz can be found anywhere in the rhyolite (a pale igneous rock), blasting is done occasionally on the private claim, making it easier to find the crystals, so we paid the fee and set to work. We located a dozen or so specimens with small (few mm) crystals in cavities in the rock, but got lucky once, finding a 13-mm (half-inch) long honey-colored crystal that was nicely terminated and transparent enough to see through it clearly!
Continuing slowly northeast through the Bonneville Basin, towards Salt Lake City, we had a few exciting encounters. One was discovering a Ferruginous Hawk nest with both adults in attendance. This magnificent raptor nests in prairies and sagebrush plains, feeding principally on jackrabbits, which are too heavy for them to carry away, so they must be eaten in place. Another highlight was discovering two individuals of Sclerocactus spinosior, a rare cactus known from just five counties in Utah and nowhere else in the world.
There were a number of locations we hoped to visit within a few hours of Salt Lake City, but COVID-19 closed all but one, the Bear River Migratory Bird Refuge NWR. The closest we could camp to the refuge was about an hour and forty minutes away. However, it was an outstanding site, with large numbers of water birds filling the huge impoundments. Birds we saw included American Avocets (my favorite bird), Golden Eagles, and Eared Grebes and Franklin’s Gulls in lovely breeding plumage. We also heard two species of frogs, Northern Leopard Frog and Midland Chorus Frog, the latter especially reminding us of many early springs in the past.
Running out of interesting Great Basin Desert sites that were open and at low enough elevation, we headed west across northern Nevada for the southeast corner of Oregon, which forms the northwest corner of the Great Basin Desert. We resupplied at Winnemucca, NV and camped in nearby Water Canyon, which had a pair of calling and mating Prairie Falcons, and beautiful aspens in the campsite (bare of leaves, of course, but with lovely pale trunks with black markings). Once in Oregon, we camped in the Diamond Craters BLM Area, right on the rim of what appeared to be a collapsed lava tube, and used this as a base from which to explore Malheur NWR. Highlights were a stunning light-phase Rough-legged Hawk, Hooded Merganser, and Trumpeter Swan, which nests on the refuge.
We had hoped to canoe in the refuge and then visit several other sites in this area and adjacent northwest Nevada, but the weather again took a turn for the worse, with a bad long-term forecast. With no signs of spring in the area, we decided to retreat again to the Mojave Desert. At least our route south through the heart of Nevada involved roads we had not driven before, with nice scenery, particularly the snow-covered Toiyabe Mountains. As I write this in southern Nevada, it’s 70 degrees and sunny, and though our plans are in disarray, it’s great to be among flowering native plants again.