We have a house in Arrrowhead and are here now. Raptors are NOT required to use changes until R2 conditions and frankly, you dont want to be on 18 or the 330 in R2 conditions. You are only required to carry them if you have M+S tires and they are legal depth and in good condition.
Sometimes they check, sometimes they ask, sometimes they wave you by. It's depends.
Autozone has a set for about $130 with tensioners. I keep them in the raptor under the rear seat when it snows.
FWIW, I've been coming to Arrowhead for nearly 35 years as a driver. I've only chained up ONCE with a 4X4 and that was in R3 and it was for safety on the 3/4 inch black ice on the road.