## 1 Introduction  
### Indigenous Land Boundary Conflicts  
One of the most difficult types of land-related conflict is that between Indigenous peoples and third parties, such as settler farmers or companies looking for new opportunities who are encroaching on Indigenous communal lands [1]. Although the number of people with communal rights is relatively small, the areas covered by communal land rights are vast and are often under pressure from the rising global demand for natural resources, raising conflict, and debate [2, 3]. This causes conflicts and land boundary disputes between the Indigenous peoples, settler farmers, miners, companies, and other spatially expanding actors [4, 5]. This article describes boundary conflicts between Colombian Indigenous reserves (resguardos indigenas) and their neighbours in the Cumaribo municipality in the Vichada department and analyses possible solutions using fit-for-purpose land administration methodology of land conflicts. These resguardos indigenas, or Indigenous reserves, are territorial divisions that, by means of a property title, guarantee a certain Indigenous community the ownership of a territory that is communally owned and traditionally inhabited by them. Boundary conflicts here raise fierce tensions: discrimination of the others, perceived unlawful occupation of land on both sides, stealing of cattle, and removing of fences. Land in Peace is a project cooperation between Kadaster, Twente University, the Dutch Embassy, and Colombia's Universidad Distrital to develop and propose an efficient land administration system for securing land rights in rural Colombia. The project works together with Colombian land institutions, such the Instituto Geografico Agustin Codazzi (IGAC), Agencia Nacional de Tierras (ANT), and Superintendencia de Notariado y Registro (SNR). The fit-for-purpose method is applied to jointly measure land with the land users, using a Global Network Satellite Systems (GNSS) antenna and a mobile collector app that was developed, and especially for the purpose improved, by Esri. Kadaster's Land in Peace project analysed the situation in three Indigenous reserves of Cumaribo (2019-2020) in cooperation with IGAC, Colombia's National Geographical Cadastral Institute Agustin Codazzi, who started updating the complete cadastre of Cumaribo. The three Indigenous reserves have different land boundary disputes with their neighbours. The first case describes a situation where Indigenous land overlaps with neighbouring settler farmers' lands. In the second case, Indigenous communities are located outside of the official reserve's boundaries. In the third case, the Indigenous community claims additional land based on local traditional knowledge that has never been recognized by the Colombian government. The fit-for-purpose (FFP) methodology was applied to map and define the overlapping land claims between the Indigenous peoples and the neighbouring settler farmers (colonos). The land boundaries were measured by each party themselves, and the resulting concrete contested areas were afterwards discussed with all of the parties involved. In several cases, both parties held official ownership documents describing the boundaries in text or with unclear maps, leaving room for different interpretations. The official map of the reserve, for instance, was drawn on a small scale, which means that this limit cannot be related to a precise location in the field. The FFP methodology aims to define, in a participatory way, a clear and transparent definition of the boundaries together with the community, whereby potential huge conflicts can be downsized to a specific area, providing a solid basis for conflict resolution. This article starts with a description of the Indigenous land situation in Colombia and describes, more specifically, the situation in the pilot region, the municipality of Cumaribo. This is followed by a description of the participatory FFP methodology that was used to measure land boundaries.