Maine State Route 121
State Route 121 is a state highway in southern Maine. It begins at an intersection with U.S. Route [302 in Maine|U.S. Route 302] and Maine [State Route 35|SR 35] in Raymond and ends in Auburn. It is signed as a north-south highway, which accurately reflects its alignment from Raymond to Oxford, but from there it runs almost due east to its terminus in Auburn. Its overall routing is roughly L-shaped.
Route description
SR 121 begins at an intersection with US 302 and SR 35 in Raymond, not far from the southern terminus of SR 85. It proceeds northward, paralleling SR 85 to the west of Panther Pond until reaching its first intersection with SR 11 in Casco. It continues north along the west side of Pleasant Lake and Thompson Lake before entering Oxford, where it turns to the east to meet SR 26 just south of the Oxford County Regional Airport. SR 121 briefly joins SR 26 in a wrong-way concurrency before splitting off southeast towards Mechanic Falls. It heads into the town center where it meets the southern terminus of SR 124 and SR 11 for a second time. From here to its terminus in Auburn, SR 121 is overlapped by SR 11.SR 11 and SR 121 proceed out of town to the southeast, meeting the southern terminus of SR 119 before entering Auburn and proceeding towards downtown on Minot Avenue. At the intersection of Minot Avenue and Rotary Street, SR 11 and SR 121 turn north on Washington Street. Prior to 2023, this intersection was signed as the northern terminus of SR 121. Continuing north, Washington Street meets the southbound lanes at Minot Avenue, then reaches the intersection of Court Street, Union Street, and Minot Avenue, where the SR 121 designation officially ends. SR 4 continues straight onto Court Street while US 202, SR 11 and SR 100 turn east onto Union Street towards Lewiston.