The regional boundary indicates the jurisdiction between York Region and neighbouring regions. The municipal boundaries define the limits of the Region's nine area municipalities: Aurora, East Gwillimbury, Georgina, King, Markham, Newmarket, Richmond Hill, Whitchurch-Stouffville and Vaughan. In 2007 an extensive investigation and clean-up of the municipal boundary locations was completed which included: snapping the boundaries to the road centrelines (which were spatially adjusted to the orthophotography in 2005); recalculating the boundary along Highway 404 to follow the 150 feet west of the centre line of the highway as outlined in the 1970 Regional Municipality of York Act; spatially adjusting the boundary along the Holland River to coincide with the centre of the river as illustrated in the 2005 orthophotography; spatially adjusting the boundary along Lake Simcoe according to the recent corrections completed by the Lake Simcoe Regional Conservation Authority according to the 2002 orthophotography; and several areas often questioned by users of the municipal boundary data were clarified in cooperation with the local municipalities.