The flood:
In 2011, a catastrophic flood engulfed the lower regions of Minot. Experts suggest this was not a hundred-year flood, but rather a 250-500-year flood event. Flooding of this incredible magnitude, by their estimations, only occurs once in 250-500 years. In 1881, a monstrous flood inundated the city, and again in 1969, but the 2011 flood shattered all previous high water records.
In the winter previous, exceptionally heavy snowfall accumulation, coupled with equally heavy rainfall in spring/early summer months (equaled annual averages in about 2 months!), caused flooding throughout southern Canadian prairie provinces. Since this watershed also feeds North Dakota’s rivers in this region, the onslaught of high water continued south of the border.
While this cache concentrates on Souris (or Mouse) River flooding in 2011, much of North Dakota was devastated by the 2011 flooding.
The Souris River flows through Minot, and originates and terminates in Canada. In normal circumstances, the river is below the 1549.0 feet elevation designating “flood” stage. 1555 feet is “major” flood stage; at 1558 feet, “record” flood stage is reached. On 26 June 2011, the river crested at over 1561 feet elevation; more than twelve feet higher than flood stage! Typical “flood” stage river flows are about 7,000 cubic feet per second (cfs); at crest in 2011, the river nearly quadrupled its flow to over 26,000 cfs. 4100 homes were lost, and over 12,000 people were left homeless.
At the icon’s coordinates is the site of two United States government flood stage markers, indicating the incredible amount of water that actually stood at that location in two major flood crests. One flood marker at about eye level is several feet below the 2011 marker, which is quite high on the pole at the coordinates.
The cache: At the coordinates, you will find two metal plates affixed to the pole. Only the one at about eye level is necessary to calculate the final. The upper plate merely gives a sobering reminder to how deeply the water inundated this part of Minot. The lower plate indicates a date, XABC, and a secondary number, DEF.
Once you find the numbers, calculate the final: N 48 14.(ABC-572) W 101 18.(DEF-641)
Sources:
https://www.ndsu.edu/ndscoblog/?p=401
http://www.nd.gov/des/uploads%5Cresources%5C744%5Cfloodrecoveryreport-2011-2.pdf
https://en.wikipedia.org/wiki/2011_Souris_River_flood