Sorry, but this comes from the dictionary, not my imagination:
http://dictionary.reference.com/browse/turf
“4. Slang.
the neighborhood over which a street gang asserts its authority.
a familiar area, as of residence or expertise:
Denver is her turf. When you talk literature you’re getting into my turf.”
So in your fevered little imagination you think that motorcyclists from all over Texas traveled to Waco to fight over who got to eat at Twin Peaks restaurant.
It doesn’t surprise me, as it’s in keeping with your dime novel view of motorcyclists and motorcycles.
You are loopy, however.