Frequent monitoring of the state of wetlands is important in order to sustain these valuable ecosystems. Reliable reference maps make this monitoring more effective. A very high resolution and reliable vegetation map with a nominal spatial resolution of 2 cm by 2 cm was created for a study area in the high moor in the Kushiro wetland, Japan. The reference map was created using aerial photography recorded in the summer of 1998 with a 35 mm, non-metric camera mounted on a balloon. The study site contains 40 wetland plant community types covering about 10 ha of the high moor. The resulting map shows that belt-like spatial patterns of typical wetland plant community groups can be clearly distinguished and confirmed through visual interpretation and spatial pattern analysis. The optimal spatial resolution for monitoring vegetation in this area using remote sensing is 0.3 m or smaller.