Tengchong, a county-level city in China’s Yunnan province, 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 two particular commodities that constitute a significant part of Tengchong’s imports from Myanmar: timber and amber. In so doing the paper makes three interconnected arguments. First it argues that the trade in timber led to a particular configuration of cross-border infrastructure in Tengchong. Secondly, it shows how an illicit market – both commodities were, at different times, exported illegally from Myanmar – took shape with the active support of the local Tengchong government. Lastly, it argues that the current push for trans-national connectivity brought together under the Belt and Road Initiative umbrella, while targeting illicit practices on the surfaces, allows them to persist in different forms. The notion of "passage" (tongdao), and the way it is used by local Chinese Communist Party officials in Tengchong, is used in the paper to address this particular ambiguity.