We investigated whether trumpeter swans (Cygnus buccinator) gain energy from forage in excess of estimated daily demands while present in a spring migration stopover area west of Calgary, Alberta. We estimated energy budgets from activity time budgets of 443 individual focal-animal observations. We conducted exclosure experiments in ponds used by trumpeter swans to estimate consumption of Potamogeton pectinatus tubers and rhizomes, and we determined metabolizable energy of forage to assess energy intake. Our conservative estimate of forage removal indicated that energy demands were similar to gains within migration stopover areas. Therefore, trumpeter swans likely have a positive energy balance that is available for further migration and reproduction. We suggest that spring migration stopover areas could play a critical role in the further conservation of this species.