Background - The Illinois State Agency Historic Preservation Act (P.A. 86-707) mandates state government to preserve, restore, and maintain the historic resources of the state. Activities that can result in change of historic properties undertaken, supported or administered by a State agency are subject to review by the Illinois Historic Preservation Agency (IHPA). The IHPA also regulates private undertakings which require a permit from a State agency. Private undertakings that will affect a documented archaeological site or an area with a high potential for archaeological resources, must inventory and assess the scientific and historic potential of archaeological and historic properties within the project area. The Illinois State Museum (ISM) is responsible for preparing maps illustrating areas with a high probability for archaeological resources.
Based on the statewide distribution of documented archaeological resources, a high probability area "means any occurrence of Cahokia Alluvium, Carmi Member of Equality Formation, Grayslake Peat, Parkland Sand, Peyton Colluvium the Batavia Member of the Henry Formation, or the Mackinaw Member, as mapped by Lineback et al. (1979) at a scale of 1:5000,000 within permanent stream floodplains and including:
1) 500 yards of the adjoining bluff line crest of the Fox, Illinois, Kankakee, Kaskaskia, Mississippi, Ohio, Rock, and Wabash Rivers and 300 yards of the adjoining bluff line crest of all other rivers or,
2) a 500 yard wide area along the shore of Lake Michigan abutting the high water mark."
Any hardcopies utilizing DNR data sets shall clearly indicate their source. If the licensee has modified the data in any way they are obligated to describe the types of modifications they have performed on the hardcopy map. Licensee specifically agrees not to misrepresent DNR data sets, nor to imply that changes they made were approved by DNR.
1) The extent of the seven quaternary deposits mentioned above were hand-digitized by ISM personnel from Lineback (1979) from county size tiles that had been photo enlarged to 200 percent, making as effective digitizing scale of 1:250,000.
2) Hydrology was clipped from the 1:100,000 USGS DLG data and permanent streams, wide streams, and shorelines were extracted. All ponds were then removed to produce a simple line coverage.
3) The boundaries of Cahokia Alluvium were used to simulate the bluff edge.
4) Those portions of Cahokia Alluvium associated with one of the 8 large rivers mentioned in the bill were extracted.
5) The Cahokia Alluvium was buffered by 500 meters near the big rivers and 300 meters elsewhere.
6) A buffer of 300 yards was produced around all permanent streams not associated with Cahokia Alluvium on the Lineback map.
7) A small amount of edge matching was done at county boundaries, although some discrepancies still exist.
APPEND ARCHMOD POLY <list of 102 coverages> END
The coverage was then cleaned, dissolved, and converted to a shapefile:
CLEAN ARCHMOD ARCHMOD2 0.002 0.002 POLY DISSOLVE ARCHMOD2 ARCHMOD3 HIGHPROB POLY ARCSHAPE ARCHMOD3 POLY archmod_py.shp
The data were then reprojected to lon/lat NAD83 using the Project function of ArcToolbox:
Executing (Project_1): Project C:\archmod_py.shp C:\archmod_py_Project GEOGCS['GCS_North_American_1983',DATUM['D_North_American_1983',SPHEROID['GRS_1980',6378137.0,298.257222101]],PRIMEM['Greenwich',0.0],UNIT['Degree',0.0174532925199433]] NAD_1927_To_NAD_1983_NADCON Executed (Project_1) successfully.
HIGHPROB - Areas of High archaeologic potential, Illinois State Agency Historic Preservation Act (P.A. 86-707)
0 - not high potential
1 - area of high archaeological resource potential
In no event shall the DNR have any liability whatsoever for payment of any consequential, incidental, indirect, special, or tort damages of any kind, including, but not limited to, any loss of profits arising out of use of or reliance on the geographic data or arising out of the delivery, installation, operation, or support by DNR.
Illinois Natural Resources Geospatial Data ClearinghouseGenerated by mp version 2.8.25 on Thu Apr 02 09:53:57 2009