This paper presents updated estimates for state-level capital and investment for 1950 to 2015. We improve upon the procedure of Garofalo and Yamarik (2002) and Yamarik (2013) by using quantity measures to apportion the mining capital stock and a geometric pattern of depreciation to derive investment data. In an empirical application we use our data to estimate the production function and a simple growth model. We find coefficient estimates that support constant returns to scale and a 1/3 output elasticity of capital. These results are consistent with past regional and cross-country papers, supporting the plausibility of our data.