In order for your location as given by GPS to be useful, a round trip to a server is made to convert that information into a street address. This geocoding could be done client side, but for practical purposes, it's not. This is even moreso for additional external information mobiles use to better locate you, such as known WiFi access points, "beacons" and cell tower IDs.

All of that server traffic is logged (by both Apple and your carrier), and can be requested by law enforcement if needed. Regardless of what Apple marketing and lawyers would like you to think, your phone is being tracked in real time, always. Always.