The Hydrogeomorphic (HGM) Approach is a method for developing functional indices for specific wetland subclasses based on reference data and the protocols used to apply these indices to the assessment of wetland functions at a site-specific scale. It has been argued that the data collection and analysis process for HGM assessments are overly burdensome for routine application. This HGM rapid assessment procedure for the natural forested wetlands of the Arkansas Delta (HGMRAP) attempts to retain the classification and wetland subclass-specific reference data that correctly grounds the HGM approach, with the ease of use of a rapid assessment. In addition a module for Greentree Reservoirs (GTRs) was created. The original HGM reference data did not include managed systems, such as GTRs, and so the normal HGMRAP procedures cannot be appropriately applied to them. In addition, GTRs are managed to maximize a single function: to attract waterfowl. As such, they have different threats and require different ‘early warning' variables than those used in assessments of more naturally functioning forested wetlands.