Systematic Removal of Karst Blind Valleys from Digital Versions of USGS Topo Maps
E. Calvin Alexander, Jr.
Professor Emeritus
Earth and Environmental Sciences Dept.
Univ. of Minn. Minneapolis
MGWA Spring Meeting, MN Arboretium, I May 2025
��York Blind Valley�23V5 (23V0000005)��sec 21, York Twp.���Clipped from the��USGS 1965 Cherry Grove � 7.5’ Topo Map��10 ft. contours��
York Blind Valley dye traced to Odessa Spring
Minnesota Groundwater Tracing Database
York Blind Valley��(23V0000005, 23B0000036)�sec 21, York Twp.���Clipped from the��USGS Cherry Grove MN
7.5” Quadrangle�2008 Lidar Digital Elevation Model ��10 ft. contours
York Blind Valley
�23V5 (23V0000005)�sec 21, York Twp.���Clipped from the��Online Digital
2010, 2013, 2016 & 2019
Cherry Grove �USGS 7.5’ Topo Map��10 ft. contours�
“ … this was not a 'Cartographer' error but an automated cartographic process issue. The error was actually in the mis-identification in the hydrography (NHD) coded as a connector instead of an underground conduit. The automated process assumed it was an above ground feature and burned it into the elevation.
As far as other 'blind valley' situations I am not aware of any, but I haven't gone looking either. With limited band width we will have to rely on user reported issues to identify these. Similar issues may exist if NHD editors incorrectly identified the 'underground conduit' features as 'connectors’.
Mitch Bergeson, National Map Liaison – IA, MN, WI, USGS National Geospatial Program, mbergerson@usgs.gov (715) 670-8478
York Blind Valley
(23V5)
�sec 21, York Twp.��Clipped from the�online digital
USGS Cherry Grove MN/IA
7.5’ Quadrangle Map
2022
�10 ft. contours�
York Blind Valley
(23V5)
�sec 21, York Twp.��Clipped from the
Online digital
�USGS Cherry Grove MN/IA
7.5’ Quadrangle Map
2023 �
10 ft. contours�
Cherry Grove Blind Valley SNA to Canfield Big Spring
The blue line is the first ~0.75 miles of the underground flow path from the Cherry Grove Blind Valley SNA to Canfield Big Spring – which is the head of perennial flow in lower Canfield Creek. This passage was mapped via Goliath Cave (at low flow) and ends in a sump.
The black lines show diagrammatically dye trace connections. The sump in Goliath’s Cave is about 2. 1 miles to Canfield Big Spring to the NE.
Cherry Grove Bind Valley Scientific and Natural Area
Lidar Shaded Relief Map
2 ft Lidar Contours & Goliath’s Cave
1965 Wykoff USGS 7.5’ Topographic Map
2008 Lidar Shaded Relief Topographic Map
Fairview (23V01) and LeFever (23V2) Blind Valleys
1965 Wykoff 7.5’ USGS Topo Maps 2022
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