I do most of my riding in Ogemaw county and there you are allowed to ride your bike or quad under 25MPH on the side of a county
to or from a marked ORV trail. Last I heard Roscommon was starting to loosen up some of there laws also, not sure if they have yet or not but ill be able to find out on Labor day weekend.
Also Ive also been told that if its a blank orange diamond its for snow mobiles only (Drives me insane). There are only a couple of trails I know of that actually have bikes or quads on the diamonds.
The best way to make yourself bulletproof legal is to plate your bike, which im going to assume you have from your picture. That's what I did to my XR600R and im able to ride it (almost) anywhere. Plus I use it when im at home as a dual-sport to save some gas.
Sorry I couldn't be more of a help. I haven't looked in to the laws lately so Ill have to ask some buddies up north next time Im up. Goodluck though maybe Ill see you on the trails sometime.