This study evaluated the effect of using AR technology to develop environmental literacy (RQ1), motivation (RQ2), and perceived cognitive load (RQ3) among high school students. The sample of participants in this study included 155 10th -grade students in general education. They took a semester-long Natural Resource Ecology course. The participants were randomly assigned to one of two groups: experimental (n = 77) and control (n = 78). The use of the immersive application in the experimental group was the only difference between the learning approaches. The main research method was a questionnaire based on three scales: "The Environmental Literacy scale," "the Motivation scale," and "the Cognitive Load scale." To compare the results between the groups and make intra-group comparisons of the periods before and after the intervention, the study use the Student's t-test (p < 0.05). The findings show that the positive effect of the immersive application-based course on students was sufficiently noticeable in terms of environmental literacy (d = 0.612) and motivation (d = 0.673). At the same time, its effect in reducing the cognitive load was slightly more than average (d = 0.549). This evidence represents essential information for potential improvements to programs and courses using technology for environmental and nature conservation education. The findings of this study enable curriculum modifications for high school students. The integration of immersive technologies into education develops and enhances their environmental knowledge and skills. Future research includes introducing and studying a separate ecology course in elementary school.