Conversation so far:
where did the los angeles angels come from
The Angels were originally based in Los Angeles and were owned by “Singing Cowboy” Gene Autry.
what sport do the los angeles angels play
The Los Angeles Angels are an American professional baseball team.
what are the los angeles angels' team colors
The Los Angeles Angels' colors are red, navy blue, and silver.

Question: who are the team's main rivals
Self-contained rewrite: who are the los angeles angels' rivals