"Hazel Prarie Karst". Annotated by: Ronald C. Spong 1992. 24k USGS topo map containing dye input points, dye vectors and spring where dye was detected. Positive traces from Matheson Blind Valley and Oslund Drain to Trout (Big) Spring and Blackrock Spring. Some other miscellaneous springs and sinks documented throughout.
Spong, Ronald C.
Greenleafton B 24K USGS DRG Topo Map.
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