The challenges and successes of planning, implementing, and evaluating a nature-based four-year-old kindergarten program are shared as well as a description of the first years of the program that is designed to enhance the students' academic, physical, social, and emotional development. In addition, a description of how the partnership among a wildlife sanctuary, city, public school district, and university to create this program is provided. "Purposeful play" and ideas from European forest kindergartens are guiding philosophies for much of what we do. Forty students (twenty each in morning and afternoon sessions) have been enrolled for each of the past five academic years. They are taught by a licensed teacher and an experienced naturalist. The enacted curriculum meshes the kindergarten readiness requirements from the public school district with the natural resources from the sanctuary. There has been a waiting list of students each year wanting to enroll in the program. Plans are currently underway to double the size of the program, and parents have been asking the school district to develop a nature-based track through the K-8 curriculum.