Montana does have a hording law:

Section 4. Unconscionable pricing prohibited. (1) During a declaration of a state of emergency or a finding of an abnormal market disruption, a person may not offer for sale at an unconscionable price an essential good or service, at retail or wholesale, within the affected area.

(2) A price is prima facie unconscionable if it is 10% or more above the average price charged by a person for the essential good or service during the 30 days before the declaration of a state of emergency or the finding of an abnormal market disruption.

(3) If a person did not offer for sale an essential good or service, at retail or wholesale, within an affected area during the 30 days before the declaration of the state of emergency or the finding of an abnormal market disruption, it is a prima facie violation of subsection (1) to charge a price that represents a gross disparity from the price at which the good or service was readily obtainable in the affected area during the 30 days immediately before the declaration or finding.

Section 5. Hoarding prohibited. During a declaration of a state of emergency or a finding of an abnormal market disruption, a person may not engage in hoarding an essential good or service.

This section would be the one that appropriate, but they say only the hoarding of "...essential good or service."