There are seven types of aquatic resources on the Grand Portage Reservation. An ecological monitoring program was proposed for these resources. Some of the resources are pristine, while others have been affected by development. Each type of resource has physical (habitat, sediment, and hydrology), chemical, and biological (fish, invertebrates, and algae) characteristics that are monitored in a consistent manner so that change may be detected. Not all aspects of the physical, chemical, and biotic components are monitored at each resource type. Monitoring is focused on those aspects most susceptible to change. Replication and comparison with pristine components are a significant part of the program so that actual change can be determined from natural temporal and spatial variability.