Yes, PRESIDIO is a Scrabble word!

Letter values in Scrabble US: P 3, R 1, E 1, S 1, I 1, D 2, I 1, O 1.

Is it a valid word?

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

a fortress established in the southwestern United States by the Spanish in order to protect their missions and other holdings