Saturday, December 4, 2010

Maps To Go Offroad By

"Don't leave home without one" is a great idea – especially if you are talking about a map. I've even had a person tell me that he wasn't lost, he just wasn't on the map for a few hours.

Offroading Home has posted previously about the where's and why-fore's of mapping, in fact several times. You may remember that not too long ago, I completed an entire "101" series on the subject:

All that is well and good, but actually being able to use one effectively on a trip takes shear practice and experience. I know a couple of people with such good spatial perception that their head seems to be a TOPO map (I'm looking at you Charlie); but, most of us just seem to need to have the 'larger view' of some lines on a paper in order to get our bearings about where we are in relation to the scheme of things.

Detail vs. Scale

In fact maps seem to be always a compromise between detail and scale. The more area a map covers (higher the view) the less detail that it is able to show. So, when you are really offroad looking for that long-ago-closed old mine you are going to need pretty much all the detail that you can get. Like that contained in the USGS 1:24,000 series, quadrangle, 7½ minute – or just 'quad' for short.

I have never been lost, but I will admit to being confused for several weeks.”
Daniel Boone
To get that amount of detail however, the map (even the size of the USGS TOPO) can only show 61 square miles. That means that almost any offroad trip you take will cover AT LEAST more than two maps and perhaps as many as five, six or more. From one map, through a corner of several others and into yet another adds up quickly. When you get to buying those things by the half-dozen it can get kinda pricey, especially if you want to ride more than once a month.

Some of us have tried to use those DeLorme State Atlases. They cover an entire state and are (comparitively) less expensive. However, they are at a scale of 1:250,000 which makes them fairly useful for automobile travel, less useful for offroading and only 'better than nothing' as far as finding ghost towns are concerned.

30 x 60-minute

Most offroaders with any experience feel that the 'largest' area any one map should attempt to cover and still be useful (at least on the market today) is that given in the 1:100,000 scale – which is that used by the USGS to cover 910 square miles.

To look at it in terms of one of our recently published maps (Death Valley) at that scale it takes seven maps to cover the area! (Eight to cover Clark Co., Nevada) You do get to see mountains, canyons, major washes and roads. The thicker the red line the better the road which makes it frequently difficult to tell the difference between an actually graded dirt road and one with mere tire-tracks in the sand.

On the 1:100,000, some but not all jeep trails are shown, and even some (but few) cultural features like cabins, mines and foot trails; depending, of course, on which version you have purchased. There is the straight TOPO map version published by the USGS as well as one which has been modified by the BLM to show additional data such as land ownership, restricted areas and even some road number designations. A true odditiy, often the BLM version is the cheapest – go figure.

15 & 7½ Minute

I mentioned that the 1:100,000 was the best that is currently published because the REAL best was the '15 minute' or 1:62,500 which was published up until about 40 years ago and was a great compromise between scale and detail. Perhaps for 'government downsizing' or perhaps for remunery reasons they went to the 7½ minute scale which we have today. What we lack in 'tree saving' we make up for in detail so we just need to deal with it.

Some time ago Offroading Home made it a point to begin listing the TOPO maps applicable to any one trail, when we know them. That should make it easier for you to find maps to purchase should you desire. Additionally, we have made available a TOPO FINDER map over on the 'resource page' of the web site. There you can locate a downloadable Quad map for any state in the U.S.!

Other Maps

United States Forest Service
Sometimes the best map for a forested area is one put out by the US Forest Service. There is one for each of the US National Forests which is generally an all-purpose map. They contain quite a bit of data including some (but not all) jeep trails which BLM maps don't have.

However, they don't show any contour lines. Streams, mountains, trials and other landmarks usually give plenty of general reckoning but no elevation lines are shown. So if that's important to your activity you'll need to obtain it in some other way. In any case, if your trail goes through a national forest it would pay you to have the forest map as well as any other you might want to take along. That way you won't miss any landmark there is to see along your route which may not be listed otherwise.

National Park Service
The NPS has published maps for each one of its parks. However, there is good news and bad news.

The good news is that: they're free - and that they are adequate for the majority of casual 'on-road' visitors to the area most of the time.

The bad news is that: they DON'T show topographic features such as mountains, they DON'T show all the roads (only the ones that are open), AND you nearly have to join the CIA in order to find them!

For example, in the case of the Lake Mead National Recreation Area (LMNRA) there are four maps published to cover the area but so far I've only found one place who has them – the Alan Bible Visitor Center off US-93, east of Boulder City. And even then, good luck in finding them all in stock!

Good ol' GPS

Yes, I think that it's still a good idea to carry a hard-copy map with you on all of your offroad trips; and, yes, that map should probably be the 7½ minute quad topo map (plus the USFS map if you are in a forest).

However, I have to say that taking a GPS unit along on every trip is looking more and more like a required item all the time.

Learn A Little More

Do you remember Johnny Carson? Do you remember Dean Martin? How about Foster Brooks? If you don't you must still be a kid - or just awoke from a coma. Here's a little something to jog your memory.

[[ Sorry, that's what I get for linking to YouTube. YouTube apparently capitulated to someone claiming rights of a fairly low quality, off public airways recording of John Denver and Dean Martin. Now the performance is available nowhere ]]


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