GIS Approaches to Past Mobility and Accessibility An Example From the Bronze Age Khanuy Valley, Mongolia Oula Seitsonen, Jean-Luc Houle and Lee G. Broderick Introduction Geographic Information Systems (GIS) have been frequently used in the past decades to describe and reconstruct past mobility (see e.g. Gaffney and Stančič 1991, Howey 2011, Kvamme 1999, Llobera 2000). The most common methods for examining movement patterns have been the defining of site catchment areas, either based on the Euclidean distance or relative cost of movement across the terrain, and modelling least-cost pathways and corridors (see e.g. Carballo and Pluckhahn 2007, Howey 2007, 2011, van Leusen 2002, Lock and Harris 1996, Zakšek et al. 2008). Recently several authors, for instance Fábrega-Álvarez (2006), Whitley and Burns (2008), Murrieta-Flores (2010), Llobera et al. (2011), and Mlekuz (in press) have paid attention to the wider possibilities that application of GIS mobility and accessibility analyses can offer for archaeological interpretation, moving beyond the construction of pathways or corridors and extending to broader analyses of landscape utilization and perception, also in a non-utilitarian sense (see Whallon 2006). In this chapter we describe on-going GIS analyses of past mobility and accessibility patterns in the Late Bronze Age Khanuy Valley, Mongolia c.1300–700 BC (Figure 5.1; e.g. Allard and Erdenebaatar 2005, Allard et al. 2006). GIS studies build on field research and analyses carried out in the area over the past decade (e.g. Allard et al. 2006, Houle 2009, 2010, Houle and Broderick 2011). Khanuy Valley is presently one of the few areas in Mongolia where Bronze Age research has systematically focused on locating and studying occupation areas (i.e. settlement sites; see Houle and Broderick 2011, for a discussion of the terminology used here). Earlier research has concentrated largely on monumental studies, especially on the khirigsuur monuments, the Mongolian equivalent of the kurgans encountered across the Bronze Age and Iron Age Eurasian steppe (e.g. Allard and Erdenebaatar 2005, Wright 2007). FI NAL DRAFT