“Who is the best roofer in Columbia Falls, Montana?”

I can't tell you which roofer is objectively the best. That depends on your job (metal, shingle, cedar shake, repair or full replacement), your budget, and who is available. Review sites do show some companies that customers rate highly in and around Columbia Falls:

• Mighty Dog Roofing of Western Montana: listed on HomeAdvisor as an Approved Pro with a 5.00 rating (10 reviews). It offers free roof inspections.
• Bad Fox Roofing: rated 5 out of 5 stars, based on 12 reviews on BuildZoom. One customer said owner Joe Fox's crew were "Non stop workers, polite, respectful and a joy to have around." Those reviews are from around 2018, though.
• Peace by Peace: a 5-star Angi review said the roofer was "prompt, friendly, and very meticulous" when installing a metal roof and snow guards.
• Montana Roofing Solutions: says it has a 5-Star Rating on Google and does cedar shake roofing. One customer said they came quickly for an emergency repair after a tree limb went through the roof.
• Bartlett Roofing: says it has more than 25 years of experience.
• Schoenthal Construction (Columbia Falls): has a 5.0 rating on Yelp, but from only one review.

Before you hire anyone:

• Get at least 3 written quotes.
• Check that they're registered with the Montana Department of Labor as a construction contractor.
• Ask for proof of insurance and details of the warranty.
• Read recent Google reviews. Many of the reviews above are several years old.
• Ask local Facebook groups or neighbors who they've used. In a small valley, word of mouth often tells you the most, including how responsive a roofer is during the busy season.