Yes, MONTES is a Scrabble word!

Letter values in Scrabble US: M 3, O 1, N 1, T 1, E 1, S 1.

Is it a valid word?

MONTES is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

a gambling card game of Spanish origin; 3 or 4 cards are dealt face up and players bet that one of them will be matched before the others as the cards are dealt from the pack one at a time

Also: four-card monte, three-card monte.