How do I patch a surface body with many triangle?

[evanrloughridge]

I want to turn this surface body of Yosemite Valley into a solid body but I'm not really sure how. I looked up tutorials and I found that I had to create a patch and stitch it all together but I don't even know were the surface body needs a patch because there are so many triangles. I would appreciate any advice on how to create my solid body of Yosemite Valley. Thanks!

[jeff_strater]

I just put a Mesh Repair earlier in the timeline, and left the rest of your features in place (I deleted the stitch at the end).  It produces a solid now.  Is this what you want?