This publication reports the results of an evaluation program to determine the effect of an interdisciplinary, K-12 environmental curriculum. The objectives of the evaluation program were twofold. First, to develop and validate evaluative instruments which would measure the impact of the environmental curriculum materials on students. Both cognitive and affective instruments were developed corresponding to the levels of the curriculum design. Second, to measure the degree of impact the environmental curriculum materials had on students from the twelve school districts involved in the program. This report discusses the degree to which these objectives were successfully attained. The evaluative instruments, data, and data analysis are presented for each level. The evaluation results indicate that the total curriculum package for grades K-12 does provide the educator with a program with the potential of having a significant impact. (BT)