"One thing I noted with this book as well as half a dozen others is they ignore the Grid-magnetic angle and focus on true-magnetic as though grid was only for surveyors. I wonder how many other forum members have noticed this ?
In view of the fact that such a large number of maps use UTM (with a printed overlay) in fact the Grid-magnetic is paramount."

The reason U.S. authored map/compass books use true-magnetic is that the vast majority of civilian U.S. maps are oriented to true north. When orienting a map with a compass, or when finding a map bearing using a baseplate compass as a protractor, students were taught to find a true bearing by aligning compass to map using either a map margin or a true map meridian line such as a line of longitude (some books simply advise using the UTM grid lines and ignoring grid/true differences, a poor practice). UTM grids are a relatively recent addition in U.S. topo map development and UTM positioning was given little importance in U.S. civilian topo map land navigation, particularly as UTM is metric-based, while U.S. civilian topo maps and users were inch-scale oriented. Remember, our topos mostly come from the USGS, a non-military agency with a background towards land surveying using inch-scale and geographic coordinate systems. We never really converted to the metric system, as did the U.S. military, and that provides part of the explanation.

The other reason is that most U.S. land-based recreational navigators have been uniformly taught to locate themselves on the map through terrain association with landmarks (this is the 'orienteering' sport influence), and most U.S. instructional books simply follow this trend. Even when using compass-based techniques such as resection or triangulation, the emphasis has been on locating oneself on the map via recognizable landmarks instead of finding oneself through position coordinates. Also, because of the weight, complexity, and bulk of the equipment, radio and astral-based position finding techniques were almost unknown by most hikers and backpackers.

It was felt by many authors, probably correctly, that teaching three separate 'norths' and their appropriate conversions might be beyond the capacity of many a tenderfoot land navigator.

Only in the last few years, with the advent of the compact, portable GPS, have U.S. recreational users begun to express an interest in UTM grids, metric-based map scales, and position-finding techniques using such coordinate systems. (The USGS claims it will complete its long-promised National Digital Map with user-chosen metric or inch-based scales and grid overlays to be downloaded and printed locally in place of paper maps - we'll see. Canada recently abruptly reversed its decision to discontinue its paper topos in favor of digitized downloads after a storm of criticism when it was learned that expensive, high-quality large-scale printers would be required to match the quality of former topo maps, and printed copies of the quality required could cost upwards of $25 from retail sources.)

Contrast this background with the U.K., which has 'thought metric' in land navigation for years, with handy 1:25,000 and 1:50,000 metric scale topo maps, and taught beginners to find map bearings with a compass by orienting the latter using grid lines, converting from magnetic to grid north and vice-versa. Their recreational topo map system is derived from the military, (British Army Ordnance Survey), consequently their entire teaching system is geared to a National Grid Reference System (essentially, UTM), metric systems of coordinate measurement and scale, and grid-magnetic conversions as taught by the military. Grab a British book on map/compass use and you will immediately notice the emphasis on learning UTM grids and the grid-magnetic conversion process. Another example of the effect of national preferences results from the lack of extreme declination adjustments required in the U.K. - so compasses with adjustable declination have not achieved the popularity they have in the States.

Any British map/compass book such as Wally Keay's 'Land Navigation : Routefinding with Map & Compass' will demonstrate what I'm talking about.

Tim,
You are a source of much information.
I did know that the ordinance survey maps had large Grid-True differences, but now I understand why.
Funny aviation maps are always Lat-Long and true with magnetic variation lines in magenta.
The old US Army FM (and field practice) was my early exposure or torture ?.
The USGS (and I wonder how much the old DMA is behind it too) is going to give us more goodies, well we will see and hope.
Guess it's better than false N/E in the US Surveyor Foot right Units?

I also like the way Michael Ferguson's Book has a list of the Highest Elevation in each U.S. County, in the back! [color:"black"] [/color] [email]ScottRezaLogan[/email]