MDU Resources (MDU) - 2021 Q1 - Quarterly Report

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 For the quarterly period ended March 31, 2021 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from _____________ to ______________ Commission file number 1-03480 MDU RESOURCES GROUP INC (Exact name of registrant as specified in its charter) (State or other jurisdictio ...