Abstract: Forest therapy has gained increasing attention as an outdoor therapeutic intervention for individuals with various health challenges. However, its impact on nature connection, mood states, and life satisfaction among veterans with posttraumatic stress disorder (PTSD) remains underexplored. This pilot study investigated the outcomes of a structured forest therapy intervention for U.S. veterans with PTSD using a one-group pretest-posttest design. A total of thirty-five participants (N = 35) were recruited over multiple years through a convenience sampling approach during the one-day nature camp programs for smaller groups of veterans (n = 5, on average per group). Each group engaged in a guided one-hour forest therapy walk which incorporated a standard sequence of mindfulness-based invitations on a quarter-mile long natural dirt trail in a midwestern U.S. region forest. The intervention outcomes were measured using a questionnaire that included the Connectedness to Nature Scale, Profile of Mood States, and Satisfaction with Life Scale, before and after the intervention. A Wilcoxon signed-rank test was used to compare differences in the outcomes of the intervention. The results revealed that participants reported a stronger sense of nature connection. Negative mood states, including anxiety, depression, anger, fatigue, and confusion, decreased significantly, while the positive mood state of vigor showed a notable increase. Life satisfaction was significantly enhanced following the intervention. These findings underscore several substantial benefits of structured forest therapy for improving psychological nature connection, mood, and life satisfaction in veterans with PTSD. The study provides evidence-based support for implementing structured nature immersion interventions for similar populations.