A recent study showed that less than 50 forest kindergartens or nature preschools were in operation in 2012, but as of 2017, over 250 such schools have emerged in 43 states in the United States, with estimations for continuous growth over the next decade (NAAEE, 2017). While nature-based education programs are gaining popularity in light of recent attention to alternative education models, few studies have explored developmental and formal learning outcomes for children enrolled in such programs (Leggett, 2017). Due to the novelty of the nature-based early childhood education movement in the United States, more research is needed to determine the educational advantages of this model of early learning. The present study analyzed children's measures of creative thinking before and after exposure to an integrated 13-week pilot nature preschool program which included daily nature immersive experiences and an entirely nature immersion day, Wilderness Wednesday. Children's characteristics of creative thinking were quantitatively measured using the Torrance Tests of Creative Thinking (TTCT) (Torrance, 1966, 2017) and a parent creativity characteristics inventory of their children, the Preschool and Kindergarten Interest Descriptor (PRIDE) (Rimm, 1981), and the resulting data was analyzed pre and post the 13-week pilot nature preschool program. Qualitative data was also gathered from a generic thematic analyses of children's drawings, parent reports of indoor and outdoor activities of children, and from teacher interviews addressing program implementation considerations and parameters for creative teaching. Results indicated improvements in certain domains of creativity as measured by the TTCT and PRIDE. Qualitative analysis revealed various themes associated with creativity conveyed in children's drawings, parent indications of outdoor activities, and teacher reflections of program parameters. Limitations, implications, and future directions for research related to the field of education and school psychology are discussed. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]