No entry upon real estate is deemed sufficient or valid as a claim unless an action be commenced thereupon within 1 year after making such entry and within 5 years from the time when the right to make it descended or accrued.
When Action On Claim By Entry Must Be Commenced
Mont. Code Ann. § 70-19-403, under Limitations and Adverse Possession.
Mont. Code Ann. § 70-19-403