On the Map

Topos to Go!

By Tamia Nelson
tamia@paddling.net

August 25, 2009

Staying found is mighty important to canoeists and kayakers everywhere. Of course, it's a lot easier if you have the right tools. And despite the proliferation of cheap, compact, and lightweight GPS receivers, the topographic map (aka "topo" or "quad") is still a mainstay of backcountry navigation. Canoe Country paddlers whose favorite waters lie south of the border—that's the Canada-US border!—have long relied on the maps published by the US Geological Survey. While these no longer sell for 50 cents each, as they did back in 1968, they remain a bargain at the current price of eight or nine bucks a sheet. The bad news? A single quad is seldom enough, even for day trips, and the cost adds up quickly when you buy all the maps you'll need for a longer expedition. Luckily, the USGS has now made cash-strapped paddlers an offer we simply can't afford to refuse. How does free sound? Yes, free. Free as in "free lunch." That's a pretty good deal, right? Well, you don't need to have an uncle in the business to qualify for this astonishing discount. Uncle Sam has seen to that. You just need a computer, a color printer, and a broadband connection. That's all it takes to get…

Topos on Your Desktop

It's a paddler's dream come true. Digital copies of US quads—they're known as GeoPDFs—are available for the asking from the USGS Map Store at the agency's website. (You can also view satellite images of the States and elsewhere, though these cannot be downloaded.) To begin exploring this Aladdin's cave of wonders, just go directly to the store. Or if you're already at the USGS homepage, simply click on the "Maps, Imagery, and Publications" link in the top menu bar. This takes you to a gateway page, where you'll find a link to the USGS Store on the sidebar. Click on that link and you're home free. Or are you? Well, maybe not. Finding your way to the maps you need can be a bit tricky. But it doesn't have to be. Let's see how to make it easy.

To start with, here's a screenshot showing the USGS Store entry page:

The red oval marks the link that will take you to an interactive index map, or "Map Locator." Warning! The index map won't appear if your browser doesn't accept third-party cookies. So if you find yourself staring at a blank page, check your preferences and make any necessary changes. When you've got everything put to rights, this is what you'll see:

Use your mouse to navigate around the index map and zoom in, just as you would on Google Maps. If you want, you can also change the display from "Map" (as shown in the screenshot above) to "Satellite," "Hybrid," or "Topo." (NB "Topo" is only available at larger scales.) Once you've found your way to the area you're interested in, select the MARK POINTS button in the right sidebar, position the crosshairs cursor on one or more locations, and click to flag each spot in turn. Now click on the resulting balloon markers to bring up a list of the quads available for each place. All that remains for you to do is to download the map(s) you want. Then select the NAVIGATE button in the sidebar and repeat the process to download maps from another area.

Alternatively, you can use the map's search capability. It's a bit hit-or-miss, but it's worth a try, particularly if you know the name of a map feature near your area of interest. Here's a for-instance: I wanted to download a large-scale quad showing the Blue Ledge Narrows on the upper Hudson River, so I began by entering "blue ledge" in the sidebar search window and hitting the "Go" button. But it was no go, taking me instead to a location on the eastern shore of Lake Champlain, not far from the NY-VT border. OK. On to Plan B. I figured I'd try "hudson river" next. This took me to the lower Hudson, even further from my goal than my first search. All was not lost, however. At least I was on the right river. Since the MARK POINTS button was automatically selected when my search result came up, all I had to do was click-drag my way upstream until I'd found what I was looking for. After that, it would just be a matter of placing the crosshairs…

…on the spot and clicking once more to flag the location. And that's what I did. The white box in the lower right corner of the map gave the latitude and longitude of the cursor, as well as the US National Grid reference, while the superimposed grid indicated the "map footprint" of each topo, with the sheet names highlighted in yellow. (Use the drop-down menu in the sidebar to determine which footprints—if any—you want to see.)

Now that I'd found my way to a spot near the Narrows, I thought I'd check out the "Satellite" view. Here's what I saw:

The dark ribbon of the Hudson River is clearly visible, as is the sharp south-to-east bend in the river just above the Blue Ledge Narrows. It was immediately obvious that I'd missed my target by a bit. Not by very much, though. The Narrows are only one and one-half miles to the west of the foot of Beaver Dams Rapids, which is where I'd placed the red flag. That was close enough. So after spending a couple of minutes taking in this striking illustration of the rectangular drainage pattern that's characteristic of Adirondack rivers, I switched over from the Satellite display to Topo and maneuvered my mouse right to my ultimate destination:

There was no need for me to place a second flag here, however. As the map footprints in the earlier screenshot make clear, both Beaver Dam Rapids and the Narrows are on the same quad. So it was back to Map view, where I clicked on my original red balloon marker, immediately bringing up a list of all the quads covering this area, both small- and large-scale:

The 1:25,000 Dutton Mountain quad was the map I needed, so I clicked on "download." (I could also have placed an order for a hard copy if I'd wanted one, but the GeoPDF was perfectly adequate. And the price was certainly right.) Thanks to my broadband connection, I had the 10 Mb file in less than a minute. UnZipping it took only a second more. This was the result:

And here are the Blue Ledge Narrows up close, as shown on my new GeoPDF copy of the Dutton Mountain quad:

All of which illustrates one more advantage of PDFs. You can scale a digital quad up or down to suit your needs, and print out only the bit(s) you want to take with you on the river. You can even make your own strip maps by splicing PDFs together. And that's just the beginning. The free TerraGo Desktop extends the utility of GeoPDFs still further—though if you're a Mac user, you'll have to wait a while. The TerraGo software is currently available only in a Windows version.

What's next? Well, how about…

Starting Over?

Maybe you're interested in two rivers on opposite ends of the continent. No problem. Moving on to a new search area is as simple as clicking the "Clear Markers" button. ("Reset Map" will both clear all your markers and return to the original continent-wide display.) Then just navigate to the next destination on your list. It's that easy.

Or is it? Well, I haven't encountered any problems I couldn't solve with the excellent online help, but if that day ever comes, the USGS has a toll-free telephone line. They also do e-mail, and I can vouch for the fact that they're quick to answer inquiries. Customer support simply doesn't get any better than that. So let's give credit where credit is due, shall we? At a time when government is taking a lot of hard knocks, it's only fair to recognize those agencies which give good value for money. And the USGS is surely one.

This wouldn't have surprised John Wesley Powell. His is a name that most paddlers will recognize, the naturalist turned soldier who lost an arm at the Battle of Shiloh and then, when the shooting stopped, went on to map the Grand Canyon of the Colorado. What may be less well known, however, is the fact that, later on in his life, Major Powell became the second director of the USGS, helping to shape a tradition of service that survives to this day. I can think of no better memorial to the indomitable explorer.

If you paddle inland waters, you'll need topographic maps. In fact, they belong in the chart cases of coastal kayakers, too. (But don't forget to bring proper charts, as well.) And since one map is seldom enough, even on day trips, the cost rapidly adds up. Luckily, help is at hand. The US Geological Survey has made you and me an offer we can't afford to refuse. Their GeoPDF program lets us download digital copies of US quads at a truly unbeatable price: free! The result? It's never been easier—or cheaper—to put ourselves on the map. And that's very good news, indeed.

Copyright © 2009 by Verloren Hoop Productions. All rights reserved.