High school students are introduced to STEM Careers by making parts and assembling the Tech-Explorer catapult project developed by the Sierra STEM Community Collaborative at Sierra College (sierraschoolworks.com) in Rocklin, CA through the Center for Applied Competitive Technologies (CACT). See high school students' excitement and engagements as they use hand and power tools such as mills and lathes to construct a working catapult. The project integrates fractions, geometry and other math essentials into this relevant classroom lesson. Through the applied academic experience, students' math skills are reinforced and careers in Science Technology, Engineering & Math (STEM) are introduced. This project is also used in the National Science Foundation Tech-Explorer project that further integrates math skills.