As the title says.. There used to be a Quick Links option on the grey bar at the top of the page. That would produce a drop-down menu with an option to: Mark Forums Read..

Seems to be gone now. I can't find a way to mark all the forums read after I've gone through all the new posts.

 

Click the down arrow next to your user name in the upper right. It is in that menu.

 

Great.. Thanks!