The main goal of this paper is to analyze the spatial behavior of unauthorized migrants in their attempts to irregularly cross the Czech state's “green” border (including walking trails) into Austria and Germany, between 2005 and 2007. It demonstrates the importance of select demographic and human characteristics of the migrants, as well as the physical features of the environment, in their crossing. Our main premise concerning the importance of smuggling and the more sophisticated means and strategies employed among migrants using smugglers' services (vis-à-vis those without smugglers) was confirmed.