Zoos have been under attack by animal rights groups for decades. Despite significant reforms to improve animal welfare in accredited zoos and aquariums across North America, and significant participation in animal conservation efforts globally, these attacks persist. If zoos are to continue long-term, they need to establish themselves as community resources. One way that zoos can act as community resources are as resources for science education. For zoos to establish themselves as educational resources, there first must be evidence that zoos are positively impacting the education of their visitors. To date, however, the published research is limited and the most prominent research claiming to verify the educational impact of zoos has been highly criticized. Most research on zoo education to date has focused on the education of visitors during informal zoo visits. There is even less research regarding formal zoo education programming that typically occurs during school field trips. Research investigating how current programming designed to help elementary school students learn science through a five-day school field trip would help both zoos and elementary educators understand how students learned, and what impacted learning during participation in this program. The research outlined in this dissertation helps to answer these questions through an investigation of the BIG Zoo Lesson (BZL). A case study design was used for this research because it provided an appropriate approach to understand a complex situation with several different sets of data. A total of 9 teachers and their 48 students were interviewed both before and after their participation in the BZL and observed during the five school days they spent using a zoo as their classroom. These observations included scripted observations of lessons and activities, and direct observations of selected students during their daily one-hour animal observations. Additionally, students' BZL journals were digitally scanned, producing 2628 images of student artifacts. From the cross-referenced analysis of this data, several conclusions were made. First, the BZL facilitated active STEM learning by upper elementary students. Students appeared highly engaged during these learning experiences and appeared to both gain and retain some understanding of the science concepts in these lessons. Second, learning recorded by students through student artifacts during the BZL was retained at greater rates than learning not recorded for upper elementary students. Lastly, proximity to and observation of live animals during the BZL facilitated engagement in learning for upper elementary students. It appeared that this engagement led to greater understanding and retention of conceptual knowledge. Parent chaperone behavior during daily one-hour observation periods appeared to impact student learning by impacting engagement and on-task behavior during daily one-hour animal observations. The use of activities during daily one-hour animal observations not designed to task students with conducting independent investigations utilizing science practices may have impacted student identification of their own observations as learning. Overall, the design of the BZL provided learning experiences for upper elementary students utilizing live animals and animal artifacts not available to typical elementary teachers. The use of these resources facilitated engaging active learning experiences that positively impacted student learning. The insights from this research can help to improve learning experiences for all BZL participants and inform program design for zoo educational field trips, thereby helping zoos establish themselves as community educational resources. [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.]