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Cozad, Nebraska – The Hundred Meridian No Longer What It Used To Be

April 21, 2018


The 100th Meridian marker outside of Cozad, Nebraska. Summer, 2003

  1. Cozad, Nebraska

I’ve been there a number of times, stopping on my way to visit in-laws in eastern Nebraska by the Missouri River. Have stayed there twice in a motel just off of I-80, visited the Robert Henri Museum downtown and once went out to the 100th meridian marker just west of town, Cozad Nebraska and asked Nancy to take my picture there. The main east-west street splitting the town in half, of course, Meridian Ave. And, those lucky enough to be there on August 21, 2017 could have participated in the “Eclipse on the 100th Meridian” event in town, “with activities from 10 am to 2 pm, during the high point of the eclipse that day.

Cozad is a town of a bit less than 4000, farm country right in the path of the transcontinental railroad. It’s just east of North Platte where the largest train repair shop in North America, ney in the world is located. For a short moment, like Gothenburg just to its east, Cozad was a stop on the pony express route west. I wonder what the good people of Cozad are thinking about their current loss of longitudinal prestige.

Anyone familiar with the geography of North America or agriculture on the high plains, could explain the significance of the 100th meridian longitude. It divides the continent. At least until recently, the 100th divided “the moister east from the dryer west” of North America. To the east, rainfall is sufficient so that crops can grow with a minimum of irrigation water. To its west, on the contrary, irrigation waters are required and come both from the rivers flowing east from the Colorado and Wyoming Rockies, the Ogallala Aquifer beneath the earth and that rainfall that does make it to the ground.

But now Cozad’s (legitimate claim) to be the border between moisture and aridity has lost some of its legitimacy as the farm country needing irrigation for survival have moved east. For nearly 150 years, since John Wesley Powell first noted it, the 100th meridian was an accurate indication of weather rain patterns in the country, but no longer. Decades of global warming and climate change have had their effect. The “arid west” has advanced more than 140 miles eastward to 98 degrees longitude, just a tad east of Aurora, Nebraska. It lies between Grand Island and York just off I-80. Aridity is closing in on the Missouri River and the rich river systems running through Iowa and Missouri that feed both the Missouri and Mississippi Rivers.

Male Cardinal. Arbor Lodge, Nebraska City, Nebraska. April, 2017


Although I have read that they do exist here in Colorado, I have never seen a cardinal here. Yet they are abundant east of the 100th meridian and have been a personal marker that I am no longer in the more arid regions of the high plains. Driving east from Denver to either eastern Nebraska or eastern Kansas one cannot help noticing the change in the scenery over the miles. The more arid areas of the Colorado eastern plains and western Kansas and Nebraska slowly becomes more alive, greener in a word. East of North Platte (near Cozad) in Nebraska, Salina in Kansas, the scenery changes. There are more trees, the variety of bird life  expands, the greenery, noticeably missing on the High Plains, comes into view.

In 1878 John Wesley Powell described the same scenario far more articulately than I just did:

“On the east [of the 100th meridian], luxuriant growth is seen, and the gaudy flowers of the order Compositae make the prairie landscape beautiful…Passing westward, species after species of luxuriant grass and brilliant flowering plants; the ground gradually becomes naked, with `bunch’ grasses here and there; now and then a thorny cactus is seen, and the yucca plant thrusts out its sharp bayonets.”

The changes in nature are reflected neatly in human geography. West of the 100th population sharply decreases as do the number of farms. Farms are larger to compensate for the growing infertility of the land. East of the 100th corn, a crop that needs lots of water, is grown; to the more resilient to aridity wheat flourishes.


The eastward shift of aridity was recently documented in two scientific papers in which the lead scientist is Richard Seager of Columbia University’s Lamont-Doherty Earth Observatory. One was published at Earth Interactions (2018:22 (5)) entitled “Whither the 100th Meridian? The Once and Future Physical and Human Geography of America’s Arid-Humid Divide. Part I: The Story So Far.

The second article appeared in the same journal: Whither the 100th Meridian? The Once and Future Physical and Human Geography of America’s Arid–Humid Divide. Part II: The Meridian Moves East. Earth Interactions, 2018; 22 (5). The other authors of the study are Nathan Lis of Pennsylvania State University; Jamie Feldman of Columbia Engineering; and Mingfang Tang, Park Williams, Jennifer Nakamura, Haibo Liu and Naomi Henderson, all of Lamont-Doherty.

Although the immediate effects of the growing aridity are not necessarily apparent, Seager argues that the long-term consequences are pretty much inevitable. Current models do not so much predict changes in rainfall patterns so much as increases in temperature as a result of global warming. Increasing aridity in the effected areas will put pressure on the already overtaxed and increasingly depleted Ogallala Aquifer. Large sections of cropland may become unusable or need to be converted to grazing range. Tensions over water supplies between urban and rural agricultural areas could become even nastier.




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