An unexplained Trump administration hold on construction of a state-federal project aimed at preventing invasive carp from reaching the Great Lakes was abruptly lifted this week, hours after a call to President Donald Trump by Michigan Gov. Gretchen Whitmer.

The Army Corps had halted work without explanation on the Brandon Road Interbasin Project near Joliet, Illinois, in July, leaving officials in Illinois and Michigan struggling for answers about the pause even as environmental officials warned that invasive carp were being found alarmingly close to Lake Michigan.

Then Whitmer, a Democrat, called Trump.