April 1965 marks the 50th anniversary of the record flooding of the Mississippi, Minnesota and St. Croix Rivers. The records set in April 1965 still stand in many places. The Mississippi River crested at St. Paul at 26.01 feet on April 16th and the St. Croix River crested at Stillwater at 94.10 feet on April 18th, 1965. The next closest record at Stillwater is 1.8 feet lower at 92.30 feet in April 2001.
The flooding was caused by a combination of excessively deep frost, late winter snow and heavy April precipitation that caused rapid snow melt. With the ground still solidly frozen, the water ran off into rivers and caused widespread flooding.
Web Sites with 1965 Flood Information and Photos