Looks like the lower rocker gasket? If its the rear rocker box, you should be able to lift the tank and remove the rocker box to check out and replace if needed.

 

A couple more photos:

 

I would stick with my suggestion to re-torque the cover bolts, spray it clean with brake cleaner and watch to see if it still leaks and from where.

 

Agree, you can see a wet spot going up the back side to the interface between the top 1/2 and the bottom. It also looks like the oil is in the crack going around to the front....

 

I want to thank all of your input(suggestions) for my rocker cover problem I had. I did get a chance to re-tork them and they were a lil loose. Hopefully that was my only issue, I will also keep an eye on it. Thanks again

Memo