This paper discusses the development and implementation of a locally-sourced corpus to address the specific needs of an ESL writing program. The paper begins with a description of the motivation and development of the "Corpus of Ohio Learner and Teacher English" (COLTE), a large in-house corpus consisting of assessed ESL student writing and teacher feedback from first-year writing courses. The paper illustrates research conducted within the local context using the COLTE and discusses how the program's corpus-based approach influenced curricular revisions and instructional practice. It addresses the evaluation of these efforts, challenges encountered, and considerations for building and using corpora at the program level. The paper concludes by arguing that stakeholders within programs can work collaboratively to build and use locally-sourced corpora grounded in their specific setting to explore local practices and address the English language learning and teaching needs of their own particular context.