The Tree Line USA® program, sponsored by The National Arbor Day Foundation in cooperation with the National Association of State Foresters, recognizes public and private utilities that demonstrate practices that protect and enhance America's urban forests. For certification, a utility must meet three requirements: quality tree care; annual worker training; and tree planting and education.

In 2006, Montana-Dakota Utilities Co., in conjunction with sister companies, donated in excess of $61,000 for tree planting and education throughout Montana-Dakota's service territory. Montana-Dakota is one of 115 certified Tree Line USA® utilities and the only North Dakota-based utility to attain certification. It has maintained annual certification since 2004.