We explored factors affecting outdoor classroom design by assessing attitudes and drawings from 73 sixth graders from a single middle school. Females had more favorable attitudes about the value of outdoor classrooms, were more motivated to build an outdoor classroom, and had stronger attitudes about outdoor classrooms benefiting wildlife. Regression analysis showed "prairies and native plants" and "space to learn outside" had the strongest effect on attitudes about outdoor classrooms. Drawing analysis showed specific learning interactions with a mixture of human-built and natural elements were most frequently depicted. Our results suggest students can provide valuable insights when designing an outdoor classroom.