This study utilizes content analysis to measure the prominence of six environmental themes in children's science and social studies textbooks over the period 1950–1991. Regression analysis of data from a sample of 118 textbooks reveals that textbook space devoted to forest issues has decreased since 1950. Within this shrinking space, treatments of ecological issues with regard to forests have increased, but only in science texts. All other environmental themes have decreased in prominence. The decreasing attention to forest issues in texts may be due in part to the trend of “mentioning,” the replacement of narrative text with strings of facts, in the production of textbooks. The finding that newer, more proenvironmental themes have not replaced the classical economic view of forests as commodities suggests that the growth in environmentalism in the United States since 1950 has not yet been sufficiently integrated into our culture to affect the formal education of children.