“Too thin to plow, too thick to drink” (Rio Grande)

“Too thin to plow, too thick to drink” has been said of many rivers, such as the Missouri River, the Colorado River (before it was dammed), the Platte River, the Powder River, as well as the Rio Grande. The origin of the term is uncertain; its application to the Rio Grande appears later than to other rivers.
   
 
Wikipedia: Rio Grande
Known as the Rio Grande in the United States and as the Río Bravo (or, more formally, the Río Bravo del Norte) in Mexico, the river, 1,885 miles (3,034 km) long, is the third longest river system in the United States.   
 
This Dog’ll Really Hunt:
An Entertaining and Informative Texas Dictionary
by Wallace O. Chariton
Plano, TX: Republic of Texas Press
1999
Pg. 234:
Rio Grande: Texans drop the “e” for simply Rio Grand. Translated it means “big river.” An early Texas settler once said of the river, “It is a mile wide and a foot deep, too thin to plow, too thick to drink.” 
 
Google Books
Dictionary of the American West:
Over 5,000 Terms and Expressions from Aarigaa! to Zopilote
by Winifred Blevins
Sasquatch Books
2001
Pg. 385:
TOO THICK TO DRINK, TOO THIN TO PLOW
An eloquent description of Powder River or the Platte or many another Western river with everything but enough water to get a decent drink from.
     
Wikipedia: Platte River
The Platte River is a tributary of the Missouri River, approximately 310 mi. (499 km) long in the western United States. One of the most significant river systems in the watershed of the Missouri, it drains a large portion of the central Great Plains in Nebraska and the eastern Rocky Mountains in Colorado and Wyoming. The river was highly significant in the westward expansion of the United States, providing the route for several major westward trails, including the Oregon Trail and the Mormon Trail. In the 18th century, it was also known among French fur trappers who explored it as the Nebraska River.
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The Platte drains one of the most arid areas of the Great Plains and thus its flow is considerably lower than rivers of comparable length in North America. For much of its length, it is a classic wide and shallow braided stream. During pioneer days, the common humorous description was that the Platte was “a mile wide at the mouth, but only six inches deep.” This was also used to describe William Jennings Bryan, the famous Nebraskan politician. 49ers referred to it as “too thick to drink, too thin to plow”.
     
13 July 1930, New York Times, “Boulder Dam Begins its Mighty Career” by Dr. Elwood Mead, pg. 117:
When it flood it (Colorado River—ed.) has been described as a stream too thick to drink and too thin to plow.
   
27 July 1933, Sioux (Iowa) Center News, pg. 6, col. 3:
The Missouri has the purest water of any river water in the world, scientists claim. (...) One has aptly said the water is too thick to drink and too thin to plow. 
         
Google Books
A Mid_West Adventure in Education:
Problems and Phases of Life at Park College During its Early Days
by Joseph Ernest McAfee
Kansas City, MO: Alumni Parkana Committee
1937
Pg. 132:
...declared that the Big Muddy presents a serious problem in that “it is too thick to drink and too thin to plow.”
 
4 February 1937, Van Nuys (CA) News, pg. 1, col. 2:
Colorado river froze over during cold snap in January—first time in memory of oldest oldtimers. (...) “Water looks soupy” we observed to our buddy as we drove up the river road. “Yep, too thick to drink and too thin to plow” was his reply.
     
15 March 1937, Waterloo (Iowa) Daily Courier, pg. 8, col. 6:
Crain creek was out of its banks, its waters too thick to drink and too thin to plow, while frog choristers were practicing for their summer concerts.
     
Google Books
Texas: A Guide to the Lone Star State
compiled by workers of the Writers’ Program of the Work Projects Administration in the State of Texas
New York: Hastings House
1940
Pg. 246:
This stream, often referred to as “a mile wide and a foot deep, too thin to plow thick to drink,” was forever changing its course. 
 
Internet Movie Database
Memorable quotes for
Cattle Empire (1958)
John Cord: Keep your herd pointed due East. You should hit Horse Thief Creek in about ten days.
Garth: Where are you taking them?
John Cord: Northeast.
Garth: The Dismal River… it’s bone dry, isn’t it?
John Cord: No. They’ll be able to smell it. It’s too thin to plow and too thick to drink.
Garth: Those cows will go berzerk.
     
Google Books
Heber C. Kimball: Mormon Patriarch and Pioneer
by Stanley B. Kimball
Champaign, IL: University of Illinois Press
1986
Pg. 155:
...the Platte. The consensus regarding this river was that it was a mile wide, six inches deep, too thick to drink, too thin to plow, hard to cross because of quicksand, impossible to navigate, too yellow to wash in, and too pale to paint with.
 
Google Books
A River No More:
The Colorado River and the West
by Philip L. Fradkin
Berkeley, CA: University of California Press
1996
Pg. 182:
They said of the Colorado, “Too thick to drink, too thin to plow.”
 
Google Books
Ecology of North America
by Eric G. Bolen
Hoboken, NJ: John Wiley and Sons
1998
Pg. 181:
Indeed, the mightiest of the prairie rivers, the Missouri, was dubbed the “Big Muddy” and was characterized as “too think to drink, too thin to plow.”
 
Google Books
These United States
edited by John Leonard
Nation Books
2004
Pg. 250:
Nebraska, meaning “flat water,” was a Plains Indian name for the swift, shallow, brown Platte River that streams eastward the length of the state, sistering what is now Interstate 80. The first settlers used to lament that the Platte was “too thin to plow and too thick to drink.” Locals still maintain it’s “a mile wide and an inch deep,” and Mark Twain claimed the Platte would only become a respectable river if it were laid on its side.
 
Google Books
‘Tis Herself: A Memoir
by Maureen O’Hara with John Nicoletti
New York: Simon and Schuster
2004
Pg. 138:
Tragically, two stuntmen lost their lives filming Rio Grande, though it was never made public. I was told that they had fallen while crossing the river during a scene and had drowned in the heavy river mud. Everyone always said, “The river was too thick to drink and too thin to plow.”
   
Time magazine
A Whole New World
Tuesday, Apr. 04, 2006 By NANCY GIBBS
Some places the border is a muddy river, too thin to plow, too thick to drink. Other places it’s just a line in the sand. Over the years mapmakers redrew it, wars moved it, nature yanked it all around as the course of the Rio Grande shifted.
     
Duke City Fix
4-Wheeling through History: Chasing the Rebels on the Rio Grande
by Johnny_Mango
Posted on: 04/10/07
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“Too thin to plow and too thick to drink,” as they say.