Hi Andrew - Thanks for the comments
Some replies to comments below and perhaps I will have to find a way to clarify
-Todd (posting from Steph's account)
>The Grand Canyon map is, to a great extent, very accurate and easy to
>read. In fact, it is the best map that I've found to date which
>covers the entire park. The maps contour lines are clear and
>distinct, and are marked at appropriate intervals (400 feet/121.9
### EDIT/COMMENT: I suggest you round up the meters to 122 meters. As a
comment on our topographical maps, we expect our contour lines to be at 10
or 20 metre (33 or 66 foot) intervals. Intervals of 122 metres would make
navigation that much more difficult.
-- The contour lines are actually at 80 foot intervals, with the numeric contour indication every 400 feet) The contour line interval is captured in the product description, but I'll see if I can make this read better.
>I have tried several methods to work around this omission, including using
>the 'Route' feature contained within Topo! software (also produced by
>National Geographic), but any mileage obtained by this method will
>only be approximate (particularly if the trail contains multiple
>switchbacks or other details not visible at 1:24,000 scale).
### COMMENT: In the product details you have the scale as being 1:73,530
and you mention 1:24,000 here. Are both correct?
---map is to 1:73,530; NG TOPO software will go down to 1:24,000 - it is meant to indicate that when using TOPO! software to estimate mileage, it is only as good as the software's capability.