The CLES4 (College-Level Earth Science for Secondary School Students) project will create a college-level geoscience course for which high-school students may earn college credit. The project represents a collaboration between southern California high schools and local universities. The goal of this project is to address the lack of an Advanced Placement course in Geoscience which makes it extremely difficult to expose top high school students to the geosciences at a stage of their education where it can potentially influence their selections of colleges, college coursework, majors, and career paths. The initial collaboration of CLES4 involves the teaching of an Honors Geology class at Harvard-Westlake School. The Honors Geology class will cover the same content as UCLA's Earth and Space Sciences 1F, for which the students will receive UCLA credit. This initial course offering will serve as a model for other high schools and collaborating universities. The course will adhere to California Science Content Standards and allow more California schools to teach Earth science topics that are presently rarely covered in standard high-school science classes. CLES4 is designed for students who are rarely exposed to Geoscience education in high school, despite their strong ability and interest in science. Students who take a college-level geoscience class will discover how their knowledge of fundamental Chemistry, Physics and Mathematics can be applied and integrated into a broader understanding of Earth System science. It is expected that this newly gained knowledge of Geoscience will inspire students to delve deeper into math and the other sciences in order to solve Geoscience problems. The project will work to spread this model to other schools and universities in California, and then to the rest of the country by means of teacher workshops, websites, and publications. By creating a network among high-school teachers and university faculty, the project will also facilitate mentoring and the exchange of teaching methods and curricula.