The need for long-term demographic studies on apparently healthy amphibian populations led us to undertake an intensive examination of a population of Spotted Salamanders (Ambystoma maculatum) at a small, temporary pond in Ohio. From 2005 to 2014, we captured adults and juveniles at the pond edge, individually marked a subset of adults, and examined patterns in breeding population size, sex ratios, recruitment, differences in body size over time, and survival and recapture rates. We found that this breeding population size varied 2.65-fold across 10 yr, with an overall negative trend driven by a decline in adult males, despite the fact that adult annual survival was not dependent on sex, and that males were more likely to be recaptured annually than were females. We also found that recruitment rates were low and never reached replacement values. Body sizes varied across years for adults as well as for emerging juveniles, and females lost a larger fraction of their mass in the pond than males, especially as time in the pond increased. Some demographic variables were consistent with previous shorter term studies. We found unusually low recruitment and annual recapture rates, however, in addition to a decline in males over time, which might reflect an expansion of our understanding of what is typical for this species. It might also indicate that our population was in the early stages of decline, potentially affected by changes in hydroperiod and increases in infectious disease mortality.