Narratives about the past usually trace change over time, but legal proceedings insist on the opposite: the past is fixed in time and place. For historians, the demands are very different when writing for this standard. Contexts are narrow and specific. All that matters is the moment. What happened later is irrelevant. Historian Joseph Taylor will discuss how he addressed these demands while working as an expert witness in U.S. et al. v. Washington, commonly called the "Culvert Case.” He will explain the challenges of reconstructing ecological and cultural conditions at the time of the Stevens treaties in 1854 and 1855, as well as the implications of this form of history on how we understand our own times.