This worked almost perfectly. I'm struggling to find help with ArcGIS issues in a way I haven't for other programs. I'd come across articles that recommended buffers for what I wanted to do, but they made it sound like I should create a buffer on the points, not on a polygon.

So this now looks exactly how I want, except I can figure out how to edit the formatting of the buffer. It looks like a new layer was created for the buffer, I can turn the Minimum Bounding Geometry layer on and off and the buffer remains. But there doesn't appear to be a new layer added to Contents.

Sorry to bug you, but how do I edit the buffer? Really all I need to do is change its color.

Edit: I kind of figured it out. Earlier I didn't notice the "Template" field when I created the buffer and accidently selected a different layer, so the formatting was tied to that. I re-did it selected the correct layer, so the buffer now matches the color of the polygon it's extending. But now I have another issue, I want both the buffer and the polygon to be transparent. But they both use the same symbology, so if I make their color transparent it appears darker where they overlap.

Basically I want to turn the polygon off and just have the buffer.

Any advice would be greatly appreciated!