I'm in Las Vegas and pulling an IP address from Cox in Naperville Illinois. Why?

Was at a friend's house today relocating his CenturyLink modem and when we tried to run a speed test, it was trying to connect to Wichita, KS.  I got home and the same thing was happening to me.  I then noticed a 50.x.x.x IP address which is in Illinois.  This is the first time I've ever been assigned an IP address NOT from Las Vegas (where I'm at).  

I contacted support and they of course blamed my "third party modem" that I've been using for years and suggested I get Complete Care for an extra $10/mo so they can maybe fix their DHCP servers?  I'm not sure how my modem could decide to pull an IP address from the midwest.

No, I'm not using a VPN and I'm on a Netgear CM1000 that apparently has the power to pull IP address from anywhere in the US.