The concept of colonization includes not only the first scouting trips to unfamiliar landscapes. It also includes the gradual process of learning a new environment, incorporating it into the cycle of resource procurement and transforming it into a social landscape. People's knowledge of and connectedness to a particular environment is suggested to affect the ways in which they use a landscape and, ultimately, the archaeological remains of that use. Recent archaeological and genetic studies indicate a dual-route colonization of the Scandinavian Peninsula at the end of the last Ice Age: one from the south and a second from the northeast. In southeast Norway, these events took place within two very different contexts. Whereas the first included the settling of previously unoccupied landscapes, the second involved the occupation of areas already settled by local groups, factors that are suggested to affect the rate of landscape learning among hunter-gatherer populations. So far, however, for southeast Norway there have been few attempts to discuss what the consequences of colonization and enculturation processes would entail in a mobile Mesolithic society and in different contextual settings. In this paper, we will focus on intra site studies of lithic remains (MANA) from 30 sites dated between c. 9500-7000 BC, in order to discuss long-term variation of the technological organization, spatial behavior and land use among colonizing Mesolithic groups in southeast Norway. Further, it provides a basis for discussing the complexity of landscape learning and human-environment interactions.