Most ISP's have a route they go through depending where you are before you hit their "exit" hub, and then go wherever. This isn't rerouting, but just the way it is. I live in missouri, and ping tests would show when I was with ATT it would bounce in my city, go to st louis, a couple bounces there, and then to chicago. About 6 hops or so before it went from chicago to wherever the target was.

I switched to Charter later on, and for a long time it went from my city, to kansas city, to olathe kansas, then down to houston texas.

That's the routing of the ISP. Unless you live close to the exit hub, you should choose somewhere close to it. In my situation I use the texas twitch server, as it provides better performance rather than the actual physically closest server which would be Chicago.

Also when you did the test is important and try at different times. On various days my traffic actually goes all the way to VA instead. Again this isn't throttling, it's just the "internet" and all the ISP's directing traffic when certain servers have issues or get over burdened. And last time I checked the largest data servers in the country are actually on the east coast, so it doesn't surprise me to see a lot of traffic get routed that way