Data Sources and notes

This file contains ArcView shapefile versions of the digitized 1894 Missouri River Commission Maps (#01-28) found at the following USGS website:

http://aa179.cr.usgs.gov/1894maps/index.htm

The MRC maps were vectorized using R2V software. Georeferencing was accomplished by taking a minimum of five DM coordinates from the maps and using these as control points. These points were plotted as event themes in ArcView, they were then projected to UTM27, zone 15, Clarke 1866. The resulting UTM coordinates were then assigned to the control points on the image. The georeferenced image was then exported as an ArcView (line) shapefile. In ArcView, the projection utility was used to reproject the UTM27 shapefile to UTM84 (NADCON datum shift was employed). Neither the UTM27 nor UTM84 shapefile versions of the MRC maps were tweaked in any way to align with the Landsat image. Nevertheless, the "raw" alignment is generally good.

Shapefile naming convention: P20UTM8415.shp where 

P## = plate number (20 of 83 MRC maps)
UTM8415.shp = UTM/WGS 84 projection/datum, zone 15


The maps on this disk (plates 01-28) are found in Index I, II, III, and IV. The maps correspond to Landsat images 15-35 and 15-40 [~ Missouri, Iowa, and Nebraska] posted on the University of Montana's Lewis and Clark Education Project home page located at:

http://lewisandclarkeducationcenter.com 

How to view the contents

This disk contains a "Readme" file containing the message that you are currently reading, (Mr.Sid images can be downloaded from the above website) and ArcView .shp file versions (zone 15, UTM/WGS84) of MRC maps 01-28. 

ArcView GIS software (or a GIS package that can read .shp format) is necessary. The easiest way to use these shapefiles is to download the Mr. Sid image from the above website. Copy the folder on the CD to your hard drive. Open a new project. Make sure your Mr. Sid image support extension is turned on. Open a new view and add the Mr. Sid image. Then add the maps you desire from the folder. If you are using ArcView, remember these are line files, so change your "data source type" from "image data source" to "feature data source."

Additional author notes 


UTM27 is, at the moment, an approximation for the MRC's datum. Bob Bergantino (bbergantino@mtech.edu) communicates that 

The only portion of the Missouri River Commission maps that I've worked with have been those from the mouth of the Yellowstone to the Three forks. The datum shift that I've measured from Triangulation Stations that can be identified on those maps and the 1:24,000s puts the MRC coordinates about 100 meters southeast of those based on the 1927 horizontal datum. 

I'm not sure what kind of datum the MRC used. It doesn't appear to be Astronomic, because the difference in Northing is too great for the instruments of the time, but the Easting difference might stem from an incorrect home station longitude. By this time (1880s) Bismark, ND and much of western Montana was linked by telegraph so time signals should have been available. (Bergantino to Miller, email communication 1/28/02)

As I examine the "fit" of the reprojected MRC maps over the Landsat images, it does appear that a "tweak" of about 100 meters to the northwest would generally improve alignment. In any event, I will continue to examine the datum issue, experimenting with others that might have been available. All suggestions are welcomed. Currently, I am preparing a set of projected maps that will register with each of the relevant posted Mr. Sid images. Also, during the summer of '02 I will be doing fieldwork on the river, gathering GPS coordinates of selected features that appear on both the maps and the images. These data should assist the effort to develop a best fit or shift. 

The MRC maps, based on a surveys completed in the early 1890's, record the way of the river and settlement along its banks. When superimposed on the Landsat images, they provide an instructive perspective on landscape change and the dynamic nature of the Missouri river. Those attempting to trace the progress of Lewis and Clark will find features on the 1894 MRC maps that are mentioned in the journals, but no longer visible on the satellite images of a hundred years later. 

David L. Miller
Professor and Chair
Department of Geography
SUNY Cortland
Cortland, NY 13045
607.753.2996
millerd@cortland.edu


The following trade names are referenced in this document:
ArcView is a trademark of ESRI.
R2V is a trademark of Able Software Corp.
MRSID is a trademark of LizardTech, Inc & International Land Systems, Inc.