Cloud water interception (CWI) by vegetation is a characteristic hydrological process in tropical montane cloud forests (TMCF). Its magnitude is difficult to measure directly and so artificial collectors tend to be used for comparisons between sites. However, artificial collectors say little about the actual inputs of cloud water (fog) to the vegetation. Scaling inputs via CWI from point measurements up to the watershed scale remains an important challenge. This chapter uses a combination of novel field monitoring techniques and epiphyte biomass measurements to quantify the magnitude and better understand the mechanisms of CWI in a sheltered, continental TMCF in south-western Colombia. Relationships were sought between amounts of fog water captured by complex vegetation structures including branches, leaves, and bryophytic epiphytes, for use in scaling up point measurements of fog water to the watershed scale using a simple GIS-based extrapolation.