In October 2017, the Interior Department's Office of Inspector General (OIG) launched an investigation into Zinke's use of three charter flights during his tenure as Interior Secretary.[8] In April 2018, OIG released its report, concluding that Zinke's chartered flight to give a speech to the June 2017 speech to the Las Vegas Golden Knights NHL team was authorized "without complete information" and that the speech was not official business because Zinke did not discuss the Interior Department or his role as Interior Secretary. OIG concluded that the two other charter flights, one to Alaska and the other to the U.S. Virgin Islands, "appeared to have been reasonable as related to official DOI business."[82][83]