STEM literate citizens are needed to fill the STEM jobs within the United States and to be active members of society economically, personally, and democratically. One way to develop STEM literate citizens is by implementing a STEM Learning Ecosystem (SLE). SLEs are an initiative founded in 2015 that bring together cross-sector partners to collaboratively design and deliver connected and coherent STEM learning experiences for students. This instrumental qualitative case study focused on the actions of SLE leaders by asking the question: What are the practices exhibited by SLE leaders in guiding their SLE? Data was collected from five participants via a semi-structured interview. Data analysis indicated three main findings: SLE leaders' practices vary, SLE leaders' actions vary based on the structure of their SLE, and there are common practices among the SLE leaders that can be combined into five overarching themes. Using Bolman and Deal's (2017) four-frame model, the study looked to understand how the SLE leaders conduct their practices. The analysis revealed that SLE leaders' practices align to all four frames and numerous frame combinations. This study's results indicated SLE leaders could be classified as brokers and collaborative leaders. As such, SLE leaders could benefit from differentiated training in how to be an effective broker and collaborative leader and how to think systemically. Any further research that focuses on the SLE leaders' practices and the effect of those practices on the SLE members and/or SLE functions, effectiveness, and/or influences would be advantageous to this body of literature. [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.]