At other times, it says that “the Department is unwilling to assess taxes on lands improperly or wrongly given the temporary tribal tax exemption … . This allows abuse of or intentional use of the system to create a tax vacation without consequence if the trust application is not approved.”

“The net result” of these and other alleged wrongdoings, the complaint states, “is irreparable harm to County governments and property tax paying residents.”

Revenue Department spokesperson Sanjay Talwani said that the agency does not comment on ongoing litigation. But speaking with the Missoulian in October, its chief legal counsel, Dan Whyte, said that “we follow that [administrative rule] in all of these cases and do it on a consistent basis.”

The complaint gave the department three weeks to respond. But the complaint is just part of what Decker called a “two-pronged approach.”

The other prong is the Legislature. In late September, the Montana Association of Counties adopted a Lake County-sponsored resolution calling for the Temporary Tribal Tax Exemption to be repealed. Like the lawsuit, it argues that the policy’s impact has far overshot expectations, and that “the Montana Department of Revenue has failed to implement the statute as written.”