If yoiu go to the Federation of Fly Fishers (FFF) website at www.fedflyfishers.org on the banner is a tab Instructor Certification, under this tab is a selection titled Find a Certified Instructor. This selection will take you to a search page where you can search for instructors by location, name and level of certification.
Search results show one THCI in Montana residing in Livingstone. The search shows four THCIs in Idaho.
Looks like you will have to travel to get to a THCI from the Missoula area.
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