St. Joseph Valley Parkway

Extension to I-94

East of Benton Harbor, Michigan, the St. Joseph Valley Parkway extension was under study due to environmental, economical and historical site issues. One of the environmental concerns relates to the habitat of an endangered species, the Mitchell's satyr butterfly that has its habitat in the area of the freeway extension.^[34] The 40-acre (16 ha) habitat is home to the second-largest population of the rare butterfly.^[35] This freeway connection was originally approved in 1981 as part of a final environmental impact study that included the freeway built from Niles northward to Napier Avenue.^[36] Since that approval, the butterfly was discovered in the Blue Creek Fen in the late 1980s,^[37] and it was listed an endangered species in 1992. The listing stalled construction of the freeway north of Berrien Springs.^[27] The US Fish and Wildlife Service (USFWS) issued an opinion two years later that the freeway project would jeopardize the species.^[37] MDOT was given permission to modify the previously approved freeway to cross the Blue Creek on longer bridges; the USFWS also required that any construction be done from elevated platforms,^[38] among other restrictions.^[35] In the interim, MDOT proceeded with construction of the southern portion of the last freeway segment, completing the freeway northward from Berrien Springs to the Napier Avenue interchange in August 2003.^[32]

A revised environmental impact study to account for the butterfly's habitat was approved in 2004.^[37] The study compared the original proposal for this extension that involved connecting directly to I-196 at I-94 with a pair of alternate routes that involved connecting US 31 directly to BL I-94 at I-94 near Benton Harbor with auxiliary lanes to I-196. The recommendation was to use the PA-2 version of the alternative connection to avoid the Blue Creek Fen.^[39] At the time the last freeway segment was opened in 2003, MDOT expected the remaining segment would not take much longer to complete,^[34] but funding was not available for many years.^[40] Construction of the extension was not included for this reason in subsequent MDOT five-year highway projects plans, although most of the design work and land acquisition was identified in 2013 as having been finished.^[41] Funding for the project was listed in the 2017–21 plan draft released in July 2016, which split the remaining work into three phases.^[42][43] MDOT received a federal grant for the project in December 2018,^[44] citing at that time a completion date of 2022 or 2023 for the project;^[45] construction began in June 2020.^[46] The ribbon cutting for this section occurred on September 26, 2022.^[2][47] The new routing to I-94 formally opened on November 9, 2022.^[48] Until the freeway was completed, US 31 followed a stretch of Napier Avenue, which was upgraded in conjunction with the St. Joseph Valley Parkway opening to that point, westward to I-94.^[49] This stretch of Napier remained state trunkline until 2023.^[50] The St. Joseph Valley Parkway name was applied to the new freeway section.^[51]