The overall goal of BigFoot was to provide validation of MODLand (MODIS Land Science Team) science products, including land cover, leaf area index (LAI), fraction absorbed photosynthetic active radiation (fAPAR) , and net primary production (NPP). To do so, we used ground measurements, remote sensing data, and ecosystem process models at sites representing different biomes. BigFoot sites measured 5 x 5 km in size and surrounded the relatively small footprint (1 km2) of CO2 flux towers. At each site we made multi-year in situ measurements of ecosystem structure and functional characteristics related to the terrestrial carbon cycle. Our sampling design allowed us to explicitly examine scales of fine-grained spatial pattern in these properties, and provided for a field-based ecological characterization of the flux tower footprint. Multi-year measurements ensured that inter-annual validity of MODLand products were assessed.