This study examines the mechanisms and geographic scope of the impact of university knowledge spillovers on the agricultural economy, using the case of Colorado State University (CSU) and the state’s agricultural economy. Our findings show that the spillover impacts of journal publications are rarely localized within Colorado; rather, the geographic scope of these impacts is national and even global. However, the extent to which the spillover impacts of patented knowledge is localized within Colorado is open to question because it is possible to control permissions for use, but at the same time it is impossible to limit everyone’s awareness and use of it, particularly in foreign jurisdictions where patents are not taken out by the university. The collaboration mechanism of knowledge dissemination, such as indicated by industry coauthorship on journal articles and private sponsorship of grants and contracts, which are more rivalrous by virtue of the more tacit qualities of knowledge being disseminated and because of the higher transaction costs, requires closer interaction and greater geographic proximity, which usually prevents global dissemination. Thus, we observe geographic proximity is significantly important for these channels. Finally, university start-ups are highly geographically bounded near universities because in the early stages start-up companies need support from their host university.