Yes, VAQUERO is a Scrabble word!

Letter values in Scrabble US: V 4, A 1, Q 10, U 1, E 1, R 1, O 1.

Is it a valid word?

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

local names for a cowboy (`vaquero' is used especially in southwestern and central Texas and `buckaroo' is used especially in California)