Answer:
Scale in the sentence means to climb. Context clues that hint towards this include the noun mountain and the word climb used in the second sentence.
Step-by-step explanation:
Scaling is a verb that is generally used in the context of climbing something tall like a building or mountain, so the use of the noun mountain makes it clear that the person is climbing a mountain. Since they say that they climbed down the other side, it further proves that scale means climb in the context.