The Clark Fork Watershed Education Program (CFWEP) goals are: (a) increasing students' understanding of the nature of ecological impacts within their watershed as related to historic mining damage; and (b) increasing students' sense of stewardship of newly restored landscapes. Data from 2012 to 2016 were evaluated for student knowledge gains (46 trials representing 2,395 student pre-surveys; 2,409 student post-surveys). Data from 2013 to 2016 were evaluated for students' attitudes toward science and disposition toward caring for the environment (38 trials representing 1,479 pre-surveys; 1,460 post-surveys). The results of this study support that the program's goals are being achieved. Students achieved statistically significant gains on knowledge surveys with a 33.4% overall gain pre- to posttest (p < 0.0001). Students also moved toward greater positive responses in both attitudes toward science and disposition toward caring for the environment with Cohen's "d" effect sizes of "medium effect" for caring toward the environment (d = 0.52) and "small effect" of positive disposition toward science (d = 0.24).