R bindings to a shared C++ port of the USACE-RMC Numerics and RMC.BestFit libraries for flood-frequency and extreme-value analysis. Provides probability distributions with density, distribution and quantile functions, moments, and parameter estimation (product moments, L-moments, maximum likelihood); Markov chain Monte Carlo sampling; and Bayesian, Bulletin 17C, and distribution-fitting analyses with uncertainty. Records may carry the censored observation types of Bulletin 17C -- historical and paleoflood observations known only within a range, perception thresholds, and low outliers -- and models may be nonstationary. Results are validated value-by-value against Numerics 2.1.4 and RMC.BestFit 2.0.0.