“A mile wide and an inch deep”

The Platte River in the Midwestern United States was named after the French word “platte” (meaning “flat”). In April 1889, humorist Edgar Wilson “Bill” Nye (1850-1896) wrote:
 
“The Platte river is a queer stream. It has a very large circulation, but very little influence. It covers a good deal of ground, but is not deep. In some places it is a mile wide and three-quarters of an inch deep.”
 
“A mile wide and an inch deep” (or “an inch deep and a mile wide”) quickly began to be used to describe people whose knowledge of things is superficial. The saying has been used in politics, academia and other fields.
 
   
Wikipedia: Platte River
The Platte River is a river in the Midwestern United States and Western United States, approximately 310 mi (500 km) long. It is a tributary of the Missouri River, which in turn is a tributary of the Mississippi River. The Platte is one of the most significant river systems in the watershed of the Missouri, draining a large portion of the central Great Plains in Nebraska and the eastern Rocky Mountains in Colorado and Wyoming. The river played an important role in the westward expansion of the United States, providing the route for several major westward trails, including the Oregon Trail and the Mormon Trail. It was explored in the 18th century by French fur trappers, who also knew it as the Nebraska River.
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History
The first European to discover the Platte was the French explorer Étienne de Veniard, sieur de Bourgmont in 1714, who named it the Nebraskier, an Oto word meaning “flat water”. The French word for flat, plate (pronounced plat, or platte), was later applied. The river provided valuable transportation for the fur trade between European emigrants and the Pawnee and Oto Indians.
   
Wikipedia: Edgar Wilson Nye
Edgar Wilson “Bill” Nye (August 25, 1850 – February 22, 1896) was a distinguished American journalist, who later became widely known as a humorist. He was also the founder and editor of the Laramie Boomerang.
 
Biography
Nye was born in Shirley, Maine, and adopted the name “Bill Nye” after a character in a famous poem by Bret Harte.
 
Urban Dictionary
a mile wide and an inch deep
said of a person’s knowledge, intelligence or, in some cases, opinion. put another way, you’re saying the person knows a lot about everything, but nothing about a given topic.
“That Sarah Palin sure knows foreign policy!”
“She’s all talking points. Her knowledge is a mile wide and an inch deep.”
by OuLiPo Feb 27, 2010
     
21 April 1889, Arkansas Gazette (AR), “Nye Waxes Eloquent,” pg. 5:
WEST OF THE MISSOURI,
AND STILL DOING THE
WESTWARD HO! ACT.
(...)
The Platte river is a queer stream. It has a very large circulation, but very little influence. It covers a good deal of ground, but is not deep. In some places it is a mile wide and three-quarters of an inch deep.
 
Google Books
A History:
Greeley and the Union Colony of Colorado
By David Boyd
Greeley, CO: Greeley Tribune Press
1890
Pg. 42:
The same is true of a half section purchased on the Platte below the mouth of the Thompson, and which was mostly in the bed of that stream, of which a wit has said, “it is a river three-fourths of a mile wide and three-fourths of an inch deep.”
 
Google Books
TENTH ANNUAL SESSION
OF THE
NATIONAL FARMERS’ CONGRESS
HELD AT
COUNCIL BLUFFS, IOWA
AUGUST 26, 27 and 28, 1890.
Pg. 59
It is the grandest plain ever beheld, and in the midst of it is the Platte River, the only river in the world “an inch deep and a mile wide” laying as “flat as a defeated polt cian.”     
 
25 June 1908, Washington (DC) Post, “The Platte and Some People” (From the Geneva Signal), pg. 6, col. 4:
It has been a common thing to say that the Platte is a mile wide and an inch deep and that some people are just like the Platte.
 
Google Books
April 1911, The Philistine, a Periodical of Protest, pg. 141:
And Bill (Bill Bryan of Nebraska—ed.) is n’ta bad fellow, either; but he is like the River Platte, as Opportunity Ingalls said, “an inch deep and a mile wide at the mouth.”
 
Google Books
Physiography;
The science of the abode of man
By William Berryman Scott
New York, NY: P.F. Collier & Son Company
1922
Pg. 161:
In Nebraska, the Platte River (which Bill Nye described as being “a mile wide and an inch deep,” without too gross exaggeration) is heavily overloaded, and has built up a ridge by depositing that overload and flows along the ridge.
 
Google Books
Pathways to God
By Alexander Converse Purdy
New York, NY: The Womans Press
1922
Pg. 110:
In the state of Nebraska there flows a curious river called the Platte. The natives say of it that it is a mile wide and an inch deep and that it has to be sprinkled in the summer time to keep it from blowing away.
   
Google Books
24 December 1965, Life magazine, pg. 65, col. 4:
With a few notable exceptions, urban cultural undertakings are an inch deep and a mile wide.
 
OCLC WorldCat record
A mile wide and an inch deep : the rise and decline of the freeze movement
Author: Theodore Sasson
Publisher: Waltham, Mass., 1987.
Dissertation: Senior honors Thesis—Brandeis University, 1987.
Edition/Format:  Thesis/dissertation : English
 
OCLC WorldCat record
One Mile Wide and One Inch Deep: Giving the Secondary Mathematics Curriculum More Depth with Mathematica
Author: K Peckman
Edition/Format:  Article : English
Publication: MATHEMATICA IN EDUCATION AND RESEARCH, 7, no. 4, (1998): 29-38
Database: British Library Serials
 
Michelle Malkin
“A Mile High and an Inch Deep”
By Michelle Malkin •  August 21, 2008 10:31 AM
That’s the new tagline for the Democrat convention, courtesy of the RNC.
   
OCLC WorldCat record
Mile wide, inch deep : preparing for the future of christianity in africa.
Author: Levi C Williams
Publisher: [S.l.] : Publishamerica Inc, 2010
Edition/Format:  Book : English