Answer: The linking verb is "is".
Explanation: A linking verb is a verb that links the subject to what follows the verb, which provides additional information about the subject. In that way, a linking verb is not used to show an action, but to identify a relationship between two elements in a sentence. One of the most common linking verbs is the verb "to be". In the sentence provided, the verb "is" is connecting the subject ("Montana) to the subject complement ("a state known for its beautiful recreational areas"), which further describes the subject.