| State: | MI |
| Type: | M |
| Route: | 239 |
| Map Custom: | yes |
| Map Notes: | M-239 highlighted in red |
| Length Mi: | 1.136 |
| Length Ref: | [1] |
| Established: | 1963 |
| Direction A: | South |
| Terminus A: | south of New Buffalo |
| Direction B: | North |
| Terminus B: | near New Buffalo |
| Counties: | Berrien |
| Previous Type: | M |
| Previous Route: | 231 |
| Next Type: | M |
| Next Route: | 247 |
M-239 is a north–south state trunkline highway in Berrien County in the extreme southwestern corner of the US state of Michigan connecting State Road 39 (SR 39) in Indiana to Interstate 94 (I-94). The highway was designated in 1963, and it provided the only connection from the southern end of I-94 into Indiana until 1972.
As SR 39 crosses into Michigan it becomes M-239. As soon as it crosses the border, the road curves around to the northwest where it continues through a generally rural area. The trunkline intersects Wilson Road and passes next to a commercial development. After a little over a mile (1.8 km), the road comes to its northern terminus at an interchange with I-94 at exit 1. While M-239 officially ends at the interchange, the roadway, known as Harbor Country Drive, continues to the northwest and into New Buffalo, providing access to US Highway 12.[2] Like other state highways in Michigan, M-239 is maintained by the Michigan Department of Transportation (MDOT). In 2011, the department's traffic surveys showed that on average, 6,231 vehicles used the highway daily.[3] No section of M-239 is listed on the National Highway System,[4] a network of roads important to the country's economy, defense, and mobility.[5]
M-239 always ended at I-94, even though Harbor Country Drive continues into New Buffalo. Before completion of the Indiana portion of I-94, the freeway ended at the present exit 1. A 1.1adj=midNaNadj=mid stretch of LaPorte Road was designated as M-239 in 1963 to carry traffic to SR 39, which connects to the Indiana Toll Road.[6] [7] Until 1972, when Indiana constructed their section of I-94, M-239 and SR 39 were the only connection from the southern end of I-94 in Michigan across the state line.[8] [9] That year, the highway carried more than 15,000 vehicles a day.[10]