In this session, we will describe the development process of a river table simulation entitled “Engineer a River System” within the newly opened Yawkey Gallery on the Charles River exhibition at the Museum of Science, Boston. This 24' interactive table uses a non-traditional form factor and marries a wide range of technologies to bring together the engineering design decisions and observation skills used in the rest of the exhibition. The aim of the multidisciplinary development team was to immerse visitors in understanding a river as a system, and prompt value-based conversations about the tradeoffs associated with these interactions. We will outline the evolution of this exhibit from its origins as a multi-touch table to the final, physical 3D-sculpted table that uses projection mapping on the surface and gives feedback to visitors, triggered by Hall effect switches in the table, in the form of animations, sound effects, projected text, and read-aloud text. This evolution was inspired by previous work around making digital exhibits accessible through the Creating Museum Media for Everyone project and incorporating what we have learned from prototyping digital media with visitors with a range of abilities. During development, the form factor and the content evolved together. We will present our prototyping findings, which led to the final exhibit, but can also be used for future projects. Examples include: which components aided in accessibility, such as the textures on the 3D surfaces, and which needed to be reevaluated, such as sparingly using sound effects because the additional audio sometimes added confusion. Speakers Session Leader : Emily O'Hara, Senior Exhibit Content Developer, Museum of Science Co-Presenter : Ben Wilson, Interactive Media Manager, Museum of Science MCN 2016 Presenting Sponsor: Piction New Orleans, LA