St. Clair County Road Commission undertook intersection improvements to accommodate industry traffic. Its application for a Part 301/303 permit from Michigan DEQ resulted in coordination with Michigan DNR staff.  DNR issued the Road Commission a letter requesting investigation of Sullivant’s Milkweed, known to be within 1,000 ft of the improvements.

ASTI researched the biology and key characteristics of Sullivant’s Milkweed in order to focus the field investigation.  Research consisted of review of Illustrated Companion to Gleason and Cronquists Manual, MNFI information, and the Flora of Michigan by Voss.  ASTI then conducted on-site studies during July—the season in which Sullivant’s Milkweed would be most likely to be observed.  ASTI’s report was filed with DNR on behalf of the Road Commission; Lori Sargent of DNR requested additional information on areas outside the road improvement project, and then issued DNR’s clearance letter to the County Highway Engineer.