Spatial reasoning is a gatekeeping skill for students. With it, the invisible scales of the universe become objects of wonder and curiosity in your mind's eye. Without it, students struggle to understand the mechanics of the natural world. Spatial thinking is a key science practice, and the body of literature on spatial ability, spatial learning and visuospatial skillsets is long and vast. There is however, little research on the teacher's role in fostering spatial reasoning in the classroom. The purpose of this holistic multicase study was to explore teacher perceptions about their own spatial thinking and to explore how that reasoning connected to their instructional choices in the earth science classroom. Criteria for inclusion as a case was to be a NY state certified earth science teacher, engaged in either a hybrid or full time in person instruction in the current school year. Each of the participants completed an initial interview and either a second interview or extended email exchange. All participant information was considered confidential and no demographic or geographic information is included in this study. Data collection and analysis revealed a gap between what teachers know and understand about their own spatial reasoning and what they actually teach in their classrooms. At present, the shift to NGSS has teachers concerned about how their own professional practice will need to change. This study demonstrates that teachers do teach with models, and do teach for spatial understanding, at least most of the time. Teachers are eager to get students back into classrooms and working together, and they are willing to learn more about the new standards provided there is support and communication for them along the way. Key words: spatial reasoning, spatial thinking, NGSS, NYSSLS, earth science, case study. [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://www.proquest.com/en-US/products/dissertations/individuals.shtml.]