butterfly, which has its habitat in the area of the proposed freeway. The habitat is home to the second-largest population of the rare butterfly. The freeway between Niles and Benton Harbor was planned as a series of five segments when approved in 1981. Since that approval, the butterfly was discovered in the Blue Creek Fen in the late 1980s, and it was listed as an endangered species in 1992. This listing stalled MDOT's planning and construction of the fifth freeway segment north of Berrien Springs. The United States Fish and Wildlife Service (USFWS) issued an opinion two years later that the project would jeopardize the species. 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, among other restrictions. In the interim, MDOT proceeded with construction of the southern portion of the last freeway segment, completing it northward from Berrien Springs to the Napier Avenue interchange in August 2003. A revised environmental impact study to account for the butterfly's habitat in the northern area of the freeway was approved in 2004. The study compared the original routing for this extension that involved connecting directly to I-196 at I-94 with an alternate route that involved an indirect connection via the BL I-94 interchange near Benton Harbor, converting it to be to a cloverleaf interchange, and adding additional lanes to the resulting I-94 concurrency. The study recommended using a version of the alternate connection to avoid the Blue Creek Fen, both to save money and decrease impact to the Mitchell's satyr. At the time the freeway segment opened in 2003, MDOT expected the remaining segment would not take much longer to complete, but since then, funding has not been available. MDOT did not include construction of the extension for this reason in the department's 2014–18 highway projects plan released in 2013, although most of the design work and land acquisition had been completed. Until the missing freeway segment was built, 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. MDOT's 2017–21 plan draft released in July 2016 split the remaining work into three phases. The department listed funding for only the first two of these three phases, with construction anticipated to start in 2021. On