"We investigated actions related to a US Department of the Interior (DOI) decision with respect to two Indian Tribes’ plans to jointly construct and operate a casino in Connecticut... Secretary Zinke and the COS [DOI Chief of Staff] made statements to OIG investigators with the overall intent to mislead them. We found that both Secretary Zinke and the COS made statements that presented an inaccurate version of the circumstances in which the DOI made key decisions," the OIG said in a report of the investigation.
In September 2017, Zinke returned amendments to an application by two tribes to jointly establish a casino in Connecticut without formally approving or disapproving them, prompting the tribes to sue the department in federal court for a decision.
DOI published in 2018 a notice clarifying that the amendments were considered approved and the casino opened to the public later that year. Zinke resigned as Interior Secretary in January 2019.
Zinke told investigators that he had not talked about the matter with anyone outside DOI despite evidence of conversations about the casino amendment approval with lobbyists and others, according to the report. OIG assesses that Zinke violated his "duty of candor" when answering questions regarding the interactions, the report said.
The OIG referred their findings to the US Justice Department, who declined to prosecute the matter in summer 2021, the report also said.
Zinke requested the OIG report be released after midterm congressional elections in November, when he will be on the ballot for a US House seat representing Montana, the report added. However, OIG believes that doing so would have been inappropriate and inconsistent with Justice Department guidance, according to the report.