How to Create Geocaching Trail Maps

by Dosido

as heard on the Podcacher Podcast - The podcast all about geocaching!

Why?

Often I see geocachers that print out a trail map to take along on their hike, and even couple this with satellite or topo map with the geocaches in the area. However, often times, it's difficult to easily correlate where you are on the trail map with your geocache printout. This method allows us overlay the geocache locations on the trail map.

What Do I Need?

The Map Creation Process

  1. Download or scan a trail map - and example is here: Bigelow Hollow Trail Map (right-click, and 'save as')
  2. Download (via pocket queries) or create a GPX file of the geocaching waypoints. An example is here: bigelow hollow caches.gpx (right-click, and 'save as')
  3. Fire up Google Earth, and import or drag the GPX file onto the GE window.
  4. Add the trail map as an 'image overlay', and resize.
  5. Zoom to fit the trail map, and print it out
  6. Go caching - with no wrong turns!

The Example Tutorial

I recently attended the 42 Degrees of Fun - Hike, Paddle & Picnic event held in Bigelow Hollow SP in Connecticut. This event had 20+ caches that we could seek and a rather large trail network to go along with it!

Below is a small portion of the trail map, and a topo map of the same area.

As you can see, between the cart paths, and intersecting hiking trails, knowing which trail to take would quickly become a chore, using both a trail map, and separate topo/geocache map!

Trail Maptopo map

What we'd like to do, is combine the gpx geocaching info onto the trail map itself.

Fire up Google Earth, and we'll start by adding the gpx data, and the downloaded trail map to the satellite image.

In Google Earth, goto File|Open and select the bigelow.gpx data file. If GE zooms to the general area, but doesn't show any waypoints, make sure that you've set the timeline at the top of the screen to cover all dates. (Alternatively, you can turn off the timeline feature completely by selecting View|Show Time|Never from the menu bar)


Timeline in Google Earth

Now, we'll add in the trail map: From the menu bar, select Add|Image Overlay and select the bigelow.gif file with the browse button.

image overlay
Image overlay dialog box

While the dialog box is open, name the overlay, and move the transparency slider to about 50%.

Since we need to keep this dialog box open while we edit the image, move it to the side, by clicking and dragging the title.

Now, the only thing left to do is resize the trail map and/or rotate it so that it is located properly. To resize the map, click on any of the green edges, and drag them. To rotate the image, click on the diamond shape, and rotate. To move the entire trail map, click on the central cross-hairs and move.

This is the toughest part of the map creation, and it will likely take you a few minutes to get used to moving GE around, and resizing the map. You may find it helpful to adjust the opacity of the trail map to check on your progress! I like using the corners to resize, as you can change both height and width at the same time. Once you get the hang of it, it goes very quickly.

aligned map
Aligned trail map and satellite image

Once you have a pretty good fit, move the opacity to 100% on the slider, and click 'okay' to close the dialog box, and remove the editing features from the map.

Now, the GC codes, and some Google Earth selected icons will be on the screen, taking up way too much real estate.

To edit them, right-click on waypoints in the Places window to your left, and select 'properties'.

edit waypoint

Click on the icon at the upper right, and select something less obtuse. By clicking on the 'Style,Color' tab, you can set the scale for both the label and the icon size. Here, I have chosen 0.7 for the label scale, and 0.6 for the icon scale. These change in real time, so you can see the changes before you close the dialog box.


The waypoint edit dialog box

That's it - we're done. Now, zoom out or in, and print your masterpiece. If you'd like to send it to someone else, simply select File|Email Image, or File|Save|Save Image from the menu bar.

Here's the final product: (note you can even see which are the paddle caches on Mashapaug Pond!

The final productThe Final Product