Business Loop I-15 - Great Falls

Two of the three Great Falls interchanges from Interstate 15 connect with Business Loop I-15. The southern extent commences from a trumpet interchange (Exit 278) alongside unsigned Interstate 315, U.S. 89, MT 3/200. A short freeway ensues east to the signalized intersection with 6th Street (old U.S. 89 Bypass/U.S. 91) north across the Sun River. With I-315 ended, Business Loop I-15 transitions to 10th Avenue South across the Missouri River.

East of the river, 10th Avenue South constitutes a busy commercial arterial to Holiday Village Mall, U.S. 87 (14th / 15th Streets) and the University of Great Falls. Business Loop I-15 splits with U.S. 89/MT 3-200 for the couplet of 5th and 6th Streets. The street pair take the route north to Downtown Great Falls, where a second couplet (1st and 2nd Avenue N) turns the business loop back west toward the Missouri River.

1st Avenue N carries two way traffic west from Park Drive and Gibson Park across the Missouri River to Central Avenue. Central Avenue concludes Business Loop I-15 at a diamond interchange (Exit 280).

Updated July 31, 2026