From a FB post (not from someone I know, just something shared by a friend): someone dumped some used motor oil on the road on GMR, between mile marker 10 & the Y (which Im assuming is the road down to Camp Williams aka East Fork?). Appears intentional.

I can't confirm if this is true or how much it is. In fact I've given you 100% of the information I have. Maybe if it rains tomorrow, road will get washed clean. But probably worth you guys knowing, so you can investigate relevancy to your ride next weekend.