The South Puget Sound Prairie Landscape Working Group is a 20‐year, multi‐organization partnership focusing on conserving and restoring native prairie grassland species in Washington State. This case study presents first‐hand perspectives, reflections, and lessons learned from key partners at The Washington Chapter of the Nature Conservancy (TNC), the Department of Defense at Joint Base Lewis‐McChord, U.S. Fish and Wildlife Service, Washington Department of Natural Resources, Washington Department of Fish and Wildlife, and Wolf Haven International. The interview questions are focused on finding lessons learned from members of the different organizations on the partnering process. Interviews with some of the founding partners revealed that the original partnership began with just a small group of scientists and land managers with shared missions of protecting and restoring prairie habitat and species. Communication between partners was instrumental in sharing new information on techniques to control invasive species and propagate native prairie plants, as well as information on the population and habitat requirements for four species that are candidates for listing under the Endangered Species Act. Many of the partners share resources, and have worked together on multiple cross‐agency projects over the years, which has built strong working relationships between partner organizations, expanding the scale, scope, and funding of prairie conservation. All interviewees said conflicts between partners were infrequent. A system of prioritizing projects using sub groups made up of experts in the partnership has evolved to facilitate effective decision making. Many interviewees mentioned that shared goals and values enable them to get through personnel conflicts and agree on priorities for success. While this partnership is still in progress, interviewees gave suggestions on how to build personal relationships with partners to collaborate effectively, and shared advice on how to improve the partnership process.