From USDA Land Values 2015 Summary, (click here) published August 2015
The United States farm real estate value, a measurement of the value of all land and buildings on farms, averaged $3,020 per acre for 2015, up 2.4 percent from 2014 values. Regional changes in the average value of farm real estate ranged from a 6.1 percent increase in the Southern Plains region to 0.3 percent decrease in the Corn Belt region. The highest farm real estate values were in the Corn Belt region at $6,350 per acre. The Mountain region had the lowest farm real estate value at $1,100 per acre.
One Acre = 43,560 square feet
There are 4840 square yards in an acre and 9 square feet in a square yard (4840 x 9 = 43,560).
An acre is an ancient measurement used in agriculture - it was 4 poles wide and 40 poles long. A pole is equivalent to sixteen and a half feet. So historically an acre was a strip of land 660 feet long (220 yards or one eighth of a mile) and 66 feet wide (22 yards or one eightieth of a mile).
