Characterization and estimation of times between storms are needed for stochastic storm simulation, drought studies, etc. An exploratory investigation into practical estimation of two characterization parameters was conducted using regression equations and mapping - critical duration (CD, minimum dry time between storms) and average time between storms (TBS). Relationships between CD and average monthly precipitation (P), TBS and P, and CD and TBS were explored. CD vs P yielded poor relationships, TBS vs P yielded good relationships, and CD vs TBS yielded fair relationships. Regression parameters were correlated leading to a reduction of maps required for estimating CD and TBS over a 225000 km2 area covering parts of CO, WY, NE, and KS. TBS was mapped over the 4-state area. Practical estimation methods for CD and TBS were documented. The results are useful for parameterizing a storm-generation model under development, drought studies, etc.