15

MDU RESOURCES G ROUP, INC.

construction materials and contracting industries. Rock, ready-mix

concrete, cement, asphalt and asphalt oil are just some of the products

we supply through vertically integrated operations. With 1.2 billion

tons of aggregate reserves, we will be able to meet demand

well into the future. In 2007, Knife River contributed $77 million

to earnings.

$85.7

$77.0

10%

$55.1

$54.4

$50.7

07

03

04

05

06

five-year earnings growth*

construction materials

earnings

(millions)

24%

corporate earnings contribution**

24% Construction Materials

and Contracting

* Compound annual growth rate

** Based on consolidated earnings before

discontinued operations