I seem to recall that Mike Keller accompanied the SCA people during some of the mapping program. If so, maybe he can elucidate us as to just how and why certain survey positions were chosen. (Example 1: Were the coordinates always taken at [say] the southernmost extreme of a feature? Example 2: Were the coordinates always determined at some specified distance away from the edge of a feature? etc.] All this kind of stuff in mind, where is the justification for coordinates cited to 7 (seven ! ) decimal points? Strikes me as vast overkill. At Yellowstone's latitude (and with this, I'll stick to latitude because it's a bit easier), one degree of latitude is equivalent to just about 69.055 miles. That is 364,610 feet. Multiply that by 0.0000001 gives 0.0364 feet, and that means these coordinates are supposedly accurate to within a touch more than 0.43 inch. Really? Scott Bryan In a message dated 11/11/2013 10:30:07 A.M. US Mountain Standard Tim, david.schwarz at alumni.duke.edu writes: As a result, many of the coordinates that year were only taken within roughly the same long-distance dialing area as the feature being mapped. Obviously, it doesn't matter how accurately the equipment pinpoints your location if you're not particularly close to what you're trying to map. -------------- next part -------------- An HTML attachment was scrubbed... URL: </geyser-list/attachments/20131111/3dd30306/attachment.html>