The growth of pulp and paper mills in the US from 1970 to 2000 depended mostly on size and age. Mills grew according to Gibrat's law, and post-1970 mills grew faster than pre-1971 mills. Mills stopped growing at approximately 22 years of age. But most mills survived beyond that, thus growth was not necessary for survival, but characteristic of the early phase of the mill life cycle. Less integrated mills grew slower. So did more specialized mills and more so if they produced mostly paper. Mill location was uncorrelated with growth, but location mattered indirectly by facilitating or hindering mills with growth-conducive characteristics.