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Re: Lewis and Clark Missouri Atlas
From: Paul Hirose
Date: 2003 Dec 21, 21:47 -0800
From: Paul Hirose
Date: 2003 Dec 21, 21:47 -0800
George Huxtable wrote: > > unavailable until the telegraph arrived. Presumably, modern coordinates for > those old maps have now now been obtained by correlating identifiable and > unchanging features (so, not the river-course) with modern maps on a known The Lewis & Clark atlas makers probably tied the old records to modern mapping by means of the section corners the GLO established way back when. This page from the Missouri state survey office explains better than I could: http://www.dnr.state.mo.us/geology/lndsrv/lsfaq.htm Their description is true for just about all the states outside the original 13 colonies. For example, the section corners in my portion of California were marked in the late 1850s, though the original monuments have long since been replaced by more modern and precise ones set in exactly the same locations. After they're approved by Washington, the monuments in a public land survey can't be moved. > Although the maps are all stated to be on a modern projection (Universal > Transverse Mercator, zone 15), no grid squares are shown, not even any > marks in the margins, for UTM or lat/long or anything else. There is just > no way to relate positions in this atlas to positions on any other mapping, George, have you seen the online Lewis & Clark campsite maps? http://lewisclark.geog.missouri.edu/campsintro.shtml They plot the sites on modern topo maps with the old river course added. For example, http://lewisclark.geog.missouri.edu/campsites/1804/may30camp.shtml (The red lines are the public land survey; note the 1-mile squares.) The "Interactive Map Server" at the same Web site is not so detailed, but more flexible. You can zoom in or out, pan around, turn map layers on or off, and read out coordinates. Your browser displays the numbers as you move the mouse pointer over the map. (At least, Netscape does, down in the status line.) These are UTM easting and northing in the NAD83/WGS84 datum. I verified that by measuring the coordinates of the May 30/31 camp site and entering them into Topozone's coordinate entry page: http://www.topozone.com/viewmaps.asp They produced a map of the site as it is today. Note how well the red crosshair's location matches the red star on the "campsites" map. http://www.topozone.com/map.asp?z=15&e=601110&n=4279640&datum=NAD83&u=4