Hydrologic investigations of wetlands typically use a mass balance approach where groundwater flow to and from the wetland is estimated from the residual in the water balance. This approach, however, provides no insight into residence times and flowpaths and treats the system as a black box. In general, the hydrology of wetlands is not well understood. Even less is known about the transient functioning of wetlands, which is important for nutrient and carbon cycling. In this research, a two-dimensional profile model was used to quantify groundwater flow and heat transport in a fen/stream complex in the Allequash basin in Vilas County, northern Wisconsin. The model was calibrated with head and temperature measurements collected at three sets of nested piezometers in a north-south transect. The field data were collected using both discrete and continuous sampling methods. The parameter estimation code PEST was used to calibrate the model and determine sensitivity to input parameters. Simulating both groundwater flow and heat transport helped constrain parameters that are difficult to determine, such as hydraulic conductivity of peat. A three-dimensional version of the model is being developed to help characterize stream-wetland interactions and provide a framework for understanding geochemical cycling and storage.