A popular winter joke for children is:
 
Q: Where do Eskimos/snowmen keep their money?
A: In snow banks.
 
Versions of the joke have been cited in print since at least 1958.
   
 
Google Books
December 1958, Boys’ Life, “Think and Grin,” pg. 84, col. 2:
Daffynishion: Snowbank — A place where Eskimos keep their money. — Tom Wolzien, Boulder, Colorado.
 
15 September 1973, The Citizen-Advertiser (Auburn, NY), The Mini Page by Betty Debnam, pg. 4, col. 1:
Q. Where do Eskimos keep their money?
A. In a Snow Bank.
—Chris Sciria, 6 yrs., Auburn
   
Google Books
Biggest Riddle Book in the World,
By Joseph Rosenbloom
New York, NY: Sterling Publishing Company, Inc.
1976
Pg. 107:
Where do Eskimos keep their money?
In snowbanks.
 
14 October 1988, The Advocate & Greenwich Time (Stamford, CT), Weekend, pg. 11, col. 4:
Q. Where do Eskimos keep their money
A. In snowbanks.
 
3 March 1991, The TImes-Reporter (New Philadelphia, OH), “Classy COverage,” pg. C3:
Where do SNowmen keep their money?
In snow banks.
 
Google Groups: alt.tasteless.jokes
Q’s and A’s
Saki
10/18/99
(...)
Q. Where do snowmen keep their money?
A. In snow banks.
 
Google Groups: alt.humor.puns
Puns of the Weak 1-31-03
Stan Kegel
1/31/03
(...)
Where do Eskimos keep their money?
In snowbanks (Kid’s Jokes).
 
Google Groups: alt.humor.puns
Puns of the Weak 02-07-03
Stan Kegel
2/7/03
(...)
Where do snowmen keep their money?
In snowbanks (Sarah)
 
Twitter
Haste
‏@fyrtowr
@RocktardsTweets From a friend in Canada - Q: Where do Eskimos keep their money? A: In snowbanks. 😀
8:35 PM - 21 Jan 2015
 
Twitter
Catarino House
‏@catarino_house
Q: Where do snowmen keep their money?
A: In snow banks.
#JokeOfTheDay
11:03 AM - 18 Sep 2015