Direct Answer
In Missoula, retaining wall construction work generally requires a permit when the project exceeds $5,000 or involves system replacements. Your licensed contractor should pull the permit — if they ask you to pull it yourself, that's a red flag. Unpermitted work can cause problems when selling your home.
Full Explanation
Missoula follows MT state building codes administered by the local building department. Permit fees vary by project value. All inspections must be scheduled through the Missoula building department. Keep all permit documentation — required for home resale disclosure.
Local Factors in Missoula
📍MT permit threshold: $5,000
📍Missoula building department issues local permits
📍Sales tax on materials: 0% (no sales tax)
📍Permit records are public and transfer with the home