Asked by Peter Kim from U.S.A. Can I apply Chines Visa here in L.A. for a tour plan in S. Korea?

I planned to visit to Seoul, Korea from Oct. 2 through Nov. 5, this year. At Seoul, Korea I will take a ' Beijing tour' with a group of a renowned tour company in Seoul.

I am a U.S. citizen and living in L. A. area. In this case, can I apply that to visit China here in L.A. before I leave to Korea or should I apply it in Seoul, Korea? If it is O.K. I prefer to have it here in L.A.