A modified Lincoln index was used to estimate populations of Aedes communis in 5 woodland snow pools in the Pocono Mountains of northeastern Pennsylvania. One thousand fourth instars were removed from each pool, stained with Giemsa, and replaced within 1-3 hr. A second sample was collected within 18 hr. Population estimates ranged from 8,416 to 194,000 among the 5 pools. Regression analysis indicates that larval population size can be predicted from measurements of the surface area of the pools