A party who has signed a written contract may be compelled specifically to perform the contract, even though the other party has not signed the contract, if the latter has performed or offers to perform the contract and the case is otherwise proper for enforcing specific performance.
Mont. Code Ann. § 27-1-417
Specific performance by party who signed when other party did not sign contract
En
Official source: Montana Code Annotated (Montana Legislature). Reproduced from public-domain Montana statutes; confirm against the official source for the current text. Not legal advice.