How is the Belt and Road Initiative (BRI) transforming Asian borderlands? This paper argues that the current push for trans-national connectivity, particularly in the form of large-scale infrastructural projects, is re-shaping cross-border regimes by introducing new forms of legibility and regulations. This, in turn, while excluding small- and mid-scale traders from growing cross-border exchanges, allows for the persistence of illicit practices that new regulations claim to be targeting. To make this argument I discuss the case of Tengchong, a county-level city in China’s Yunnan province that shares a 151 km long border with Myanmar. Due to its specific geographical location along one of the main trading routes between China, India, and Southeast Asia, Tengchong has a long history as an administrative, military, and trading outpost. After a few decades of enclosure following 1949 and China's covert support for the Communist Party of Burma, trade with Myanmar revived in the 1990s and constitutes todays one of Tengchong's main sources of wealth. This paper explores this revival through the history of Tengchong's three official border crossings with Myanmar – Houqiao, Diantan, and Zizhi – and that of three particular commodities: jade, timber, and amber. In so doing it makes two interconnected arguments. First it shows how an illicit market – all three commodities were, at different times, exported illegally from Myanmar – took shape with the active support of the local Tengchong government. Secondly, it argues that the current push for trans-national connectivity brought together under the BRI umbrella, while targeting illicit practices on the surfaces, allows them to persist in different forms. The notion of "passage" (tongdao) is used in the paper to address this particular ambiguity.