This paper uses the construction of India's Golden Quadrangle central highway network, together with comprehensive loan data from the Reserve Bank of India, to investigate the interaction between infrastructure development and financial sector depth. The paper identifies a disproportionate increase in loan count and average loan size in districts along the Golden Quadrangle highway network, using stringent specifications with industry and district fixed effects. The results hold in straight-line instrumental variable frameworks and are not present in placebo tests with another highway that was planned to be upgraded at the same time as Golden Quadrangle but subsequently delayed. Importantly, however, the results are concentrated in districts with stronger initial financial development, suggesting that although financing responds to large infrastructure investments and helps spur real economic outcomes, initial financial sector development might play an important role in determining where real activity will grow.