Community partnerships present opportunities for expanding students' learning experiences outside traditional classroom settings. However, under-resourced low-income communities often lack access to such opportunities. This qualitative study explores how high school teachers, community liaisons, and community partners establish and sustain collaborative partnerships to implement project-based learning experiences for high school students. Through semi-structured reflective interviews, experiences of key stakeholders from four high school sites reveal insights into partnership motivations, connective structures, the vital role of liaisons, systemic barriers, and strategies for extending partnerships into project-based learning. While community partnerships increase access to authentic learning experiences, co-designing of PBL curricula predominantly lies with teachers, offering opportunities for community partner contributions. These findings explore how school community partnerships come to be and thrive, illustrating the voices and perspectives of formal and informal educators engaged in collaborative work to deepen student learning. [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.]