The drought of the past few years in north-central Mexico underscores the need for extensive hydroclimatic data that can reveal fluctuations and trends over time, in order to establish water resource planning and mitigation measures. Using dendrochronological techniques, an 800-year streamflow reconstruction was developed for the upper Nazas River watershed in Durango. The reconstruction showed high inter-annual and multiannual hydroclimatic variability and decadal droughts were detected in the 1250s, 1320-1340s, 1370-1380s, 1440-1450s, 1460-1470s, 1650-1660s, 1710-1730s, 1790-1810s, 1920-1940s, 1970-1980s, and 1990s. Some of the droughts were longer and of higher intensity than ones observed in climate records. Extreme flow events were detected in the years 1212, 1229, 1242, 1245, 1271, 1313, 1404, 1427, 1451, 1504, 1520, 1563, 1566, 1620,1671, 1681, 1735, 1816, 1833, 1869, 1920, 1956, 1959, and 1992, and they were linked with the El Niño–Southern Oscillation (ENSO) warm phase. Water decision-makers in the Comarca Lagunera region could use this information to establish probabilities of droughts and occurrence of extreme runoff events for management purposes.