Rocks don't rock

Driving down OR 42 last night, Ryan, Bob, and I. Bob was here but just for the one night. We though we'd be spontaneous and adventuresome and go to Bagby Hot Spring. It was dark and gently raining. All was going swimmingly, then BAM! Head sized rock in the middle of the lane that couldn't be avoided. Immediate flapping sound of a flat tire. We pulled over. Damn. I have never seen such tire damage before. My rim is mangled and destroyed. The tire is ripped apart. Thankfully I have a full size spare. After we put it on and drove another mile or so we saw the "rocks" sign. Hmm. Would've been a little more helpful a mile back. Needless to say, we never made it to Bagby. Boo.