Yeesh, take it easy, guys. Wenwen was asking a simple question. Walker Valley OHV is about 1 hour south of the border, near the Mtn Vernon area. Dig out a map of Washington State and look for Big Lake. The turn-off to the OHV is at the west side of the lake. If you look for Cavanaugh Rd, that will also put you in the area of Big Lake.
Lockers aren't required unless you want to do all the obstacles. It's is imperative that you stay on the trails marked for 4x4 use (ie: stay off the ATV trails!!!). Any trail blazing will result in your ass getting kicked by the locals.
I recommend going with another vehicle. If you go by yourself, make sure you have a winch, Hi-lift, and other recovery equipment because it is easy to get high centered or wedged against trees. I'd still recommend another vehicle though. There are some spots where a rollover is a distinct possibility if you're not careful and it'll be difficult to put your vehicle back on all fours by yourself.
As for the "breaking stuff" remark, I'm sure he didn't mean it literally.
...lars