1. A method, comprising: maintaining, by a mobile device, multiple approximations of a location of the mobile device, wherein each approximation comprises an estimated geographic location of the mobile device that is determined by filtering a respective subset of location estimates received by the mobile device using a respective Kalman filter, and wherein one of the multiple approximations is designated as an active approximation; receiving, by the mobile device, data indicating an estimate of a geographic location of the mobile device; based on a distance between the estimate of the geographic location and a given approximation of the multiple approximations, updating the given approximation using the estimate of the geographic location; and providing, by the mobile device and for display, a visual indication of an estimated geographic location associated with the active approximation.