In 2007, Cate joined Round Square, a worldwide network of 150 innovative high schools in 40 countries around the world. All member schools share a commitment to the pillars known as IDEALS, which stands for Internationalism, Democracy, Environmentalism, Adventure, Leadership, and Service. At Cate you can attend regional and international conferences, go on intercultural exchanges, and participate in international service learning projects. Round Square students from other countries love their stays on the Mesa, and Cate students return from Round Square adventures with broader horizons.
In 2016 Cate Round Square headed to Los Angeles for the regional conference, sent students to South Africa for a service-learning project, had summer exchanges in Peru and Australia, and sent a delegation to the Round Square International Conference in Switzerland.