EXHIBIT 23.1 CONSENT OF INDEPENDENT PUBLIC ACCOUNTANTS As independent public accountants, we hereby consent to the incorporation of our report included in this Form 10-K, into the Company's previously filed Registration Statement File Numbers 33-85972, 33-85956, 33-79176, 33-71772, 333-3236, and 333-3066. ARTHUR ANDERSEN LLP Minneapolis, Minnesota, March 22, 2000