Thursday, May 13, 2010

I Visit the Great Basin Desert

Friends grimaced when I told them I was going to Winnemucca. They looked concerned when I told them I was going to enjoy it. My early spring visit this year was the latest in a series of winning Winnemucca road trips.

I left spring behind on the tail end of the Snake River Plain as I climbed through brown winter grass in the mountains above Homedale. In Jordan Valley, Oregon, I found cattle still snug in their green winter pastures. The low hills that lined the rest of the road to Winnemucca were wearing the green velvet of soft new plants. Above the hills bunt cake ridges were frosted with vanilla snow, which faded to a powdered sugar dusting on the mid peaks where the sun had warmed the south and west aspects.

Green vistas, occasionally dotted with puffs of pronghorn antelope, lasted for days as I visited several valleys around Winnemucca. I pondered why there has been so much less cheatgrass than before in some of them over the past several years. Other scientists, land managers and I are not short of theories, ranging from army cutworm to bacteria, fungus and drought, but we do not have a definitive answer yet. Science provides job security.

Last year's Nevada road trip was later in the season, when the valley bottoms were furnaces of shimmering earth covered with dried plants. After a day baking on the greasewood flats and sagebrush plains I reached state highway 305 where I turned north toward Battle Mountain.

I checked my DeLorme atlas of Nevada and saw that I would pass the "Great Basin Desert," according to the labeled "Unique Natural Feature" on the map. Interesting, as I had been in the Great Basin since I crossed the divide between the Snake River Plain and Jordan Valley. The Snake River flows into the Columbia near Washington's Tricities of Pasco, Kennewick and Richland and so is part of the Columbia Plateau. Rivers in the Great Basin flow into the Great Salt Lake or lose themselves in innumerable playas and salt flats in valley bottoms throughout the 200,000 square miles of the Great Basin; there is no outlet to the ocean.

I hurried on to visit the Great Basin Desert along highway 305.

I estimated the coordinates of the Unique Natural Feature in the atlas and entered them into my GPS unit. As the indicator on the navigation screen shifted from pointing ahead of me to pointing toward the west I got out of the car and followed the indicator on foot until I reached the Great Basin Desert.

The vertical orange fiberglass sign marked a survey benchmark inside the fence that separated grazing land from the highway right of way. I squeezed between the strands of barbed wire and found the benchmark, or triangulation station, placed by "Harry" from the U.S. Coast and Geodetic Survey in 1958.

No, there had not been one last attempt to find an outlet to the sea from the Nevada desert. The Coast and Geodetic Survey began life as the Survey of the Coast in 1807. Established by Thomas Jefferson, it was the first U.S. civilian scientific agency, responsible for producing accurate nautical charts. This required knowing exactly where the U.S. was. Surveyors first precisely located points atop hills on Long Island by navigating from the stars. They expanded out by triangulating from these known points to new triangulation stations, such as the one I found in Nevada.

As the country expanded west the Survey of the Coast followed it on to dry land and continued to weave their network of triangles. Renamed the U.S. Coast and Geodetic Survey in 1878, its work allowed the country to be mapped into townships, ranges and sections for homesteading. In 1970 the agency became the National Geodetic Survey (NGS) within the National Ocean Service (NOS) as part of the new National Oceanic and Atmospheric Administration (NOAA).

The original surveyors, shooting the stars in the early 19th century, could not have known that a Global Positioning System (GPS) would exist 200 years later. But their system of triangles, interlinked back to Long Island, allowed me find to the Great Basin Desert using my handheld GPS unit. I took a self portrait to celebrate.

I contacted Dave Doyle, the NGS Chief Geodetic Surveyor, who was willing to hazard a guess that there may be 30,000 triangulation stations in the Great Basin. (You can see Dave marking the population center of the U.S. after the 2000 census or ask him a question here.)

I'm tickled that my tax dollars were used to answer one of my burning questions, but Dave's answer just brings me to another question:

Why did the DeLorme company pick the triangulation station along Nevada state highway 305 south of Battle Mountain as the location of the Great Basin Desert?

No comments:

Post a Comment