I took pics!
Here's the bin, already loaded up with lots of good worm food:
And here it is with the "lid" on it. I had some left over metal sheeting from when we built the barn, and it fit perfectly as a lid. So this keeps it nice and dark and helps maintain the moisture. It's not an airtight seal which is perfect since worms need some air.
It looks smaller in the photos, but it's 12 feet long, believe it or not.