Hello Tim,
The X an Y coordinates you included appear to be valid values for a UTM system.  Those particular coordinates converted to WGS84 Lat/Long would fall on:
N 35.364771°, W 105.450965°
Or about 25 miles southeast of Santa Fe, New Mexico (that is, assuming those values are meters).  The USGS 7.5' Topo sheets were drawn using UTM projected zones, whatever the appropriate zone was for the area.  They usually have control points listed on them given in degrees, despite the map being projected in UTM, though the degrees are typically given in Degrees Minutes Seconds format.  There are usually several graticules drawn on those maps in different coordinate reference systems (State Plane, Lat/Long, and UTM), but from your XY coordinates I would bet that it's actually referenced using UTM zone 13.  In which case, in MapInfo the projection would be under "Universal Transverse Mercator (NAD27 for US)" and "UTM Zone 13 (NAD27 for US)".  Doesn't look like you are making a mistake to me, sounds more like the FAQ has the error.

Regards,
Sam Knight

Applications Specialist
Blue Marble Geographics

[EMAIL PROTECTED]
Ph: 800-616-2725 ext. 24
Ph: 207-582-6747 ext. 24
Fax: 207-582-7001
http://www.bluemarblegeo.com
and
http://www.beyondgeo.com
----------------------- Original Message -----------------------
  
From: "Ericson, Tim" <[EMAIL PROTECTED]>
Date: Thu, 9 Mar 2006 10:35:24 -0700
Subject: [MI-L] Question on Projection of TOPO 7.5 min Maps
  

 

I’m trying to import TOPO maps (MRSid format) into MapInfo.

 

The sources FAQs  say that the projection is “Decimal Degrees” – I’m not sure what that is telling me – relative to the projection Options in MI…

 

The metadata mentions UTM Zone 13 (NAD 27)

 

When I use that projection I get locations such as

 

           X Cord     459,082.52

           Y Cord   3,913,385.49

 

 

Which really makes NO sense to me!

 

I open the MRSid into OpenEV and I get the same type of X Y Cordinates.

 

 

 

I’m sure that I’m making a mistake somewhere!!!!  Have you any suggestion?

 

 

Thanks!

 

Tim Ericson

Network Engineer

Qwest Communications

On loan to Harris Corp FAA Telecom Improvement Project

 

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