Infants who have more power within the gamma frequency range at rest develop better language and cognitive abilities over their first 3 years of life (Benasich et al., 2008). This positive trend may reflect the gradual increase in resting gamma power that peaks at about 4 years (Takano & Ogawa, 1998): infants further along the maturational curve may exhibit both increased resting gamma power and more advanced language and cognitive function. Similar to other neural characteristics such as synaptic density, resting gamma power subsequently decreases with further development into adulthood (Tierney, Strait, O'Connell & Kraus, 2013). If previously reported relationships between resting gamma power and behavioral performance reflect variance in maturation, at least in part, negative correlations between resting gamma and behavior may predominate in later developmental stages, during which resting gamma activity is decreasing. We tested this prediction by examining resting gamma activity and language-dependent behavioral performance, reflected by a variety of reading-related tests, in adolescents between the ages of 14 and 15 years. Consistent with our predictions, resting gamma power inversely related to every aspect of reading assessed (i.e. reading fluency, rapid naming, and basic reading proficiency). Our results suggest that resting gamma power acts as an index of maturational progress in adolescents.