How The Map Was Made
Topographic maps provide an unparalleled depiction of the landʼs shapes, slope, water courses, vegetation and elevations. Also, these maps depict a speciﬁc location on the earthʼs surface and cover a variety of scale. The imprint of humans on the landscape are illustrated as well. Everything from road networks, hiking trails and ﬁre breaks are drawn into the natural background of canyons and ridges. Other features such as campgrounds, cabins, communication sites, reservoirs, tunnels, benchmarks, property lines and more can be found on these versatile maps. Almost all this information comes from air photos taken from approximately 60,000′ above the ground. Much field checking is required as well, however, items depicted in field checks can soon become outdated, as is the case with most topo maps today. Trail realignments take place year after year. Drawing in the trails as they really are is where I come in.
The area comprising the “Trails of Big Santa Anita Canyon” is a portion of the Mt. Wilson quadrangle. The size of the Mt. Wilson quadrangle is about 19” by 23”. One mile of distance on the land is shown on the map to be approximately 2 5/8” in length. This means, that as “the crow ﬂies”, a 7.5 minute topographic map covers about 63 square miles of the earthʼs surface. For a large scale map, this is still quite a bit of land to portray, let alone cover it on a trail!
The Chantry Flat – Mt. Wilson Trails map covers just 8 1/4” by 7 1/4” of the Mt. Wilson quadrangle. A clear piece of acetate with a 1”x1” grid drawn on it was placed over the top of the selected map section. Then, taking a large piece of drawing paper, a 6”x6” pencil grid was drawn in , creating the frame work for this hand drawn map. The working size of the Trails map is 24” wide by 36” in length, thus providing the cartographer with a large area to depict detail in a new, larger scale. This use of increasing or decreasing grid size is deﬁnitely old school, yet is a time-proven method for accurately changing the scale of any image while preserving itsʼ integrity and preventing distortion.
Before any drawing could take place on the large working section at home, the smaller clear acetate grid would have to be scanned and enlarged in sections for the ﬁeld work. Scans that encompassed a number of the 1”x1” grid sections would be printed out and then taken into the canyons of the Trails Project for comparison to the “real scene.” It was this process of comparing how the trails progressing along canyon walls and stream courses in relation to what the Mt. Wilson quadrangle depicted, that would ultimately become the heart of the project. These map revisions would be made over and over, again on numerous hikes and throughout several different seasons. Every trail and road depicted on the Trails map has been walked many times and checked for accuracy in relationship to the landscape.
After each day of drawing how the trail really covered the land, Iʼd take the drawn over scans home and transfer the image, by hand, onto the large sheet of the drawing paperʼs 6”x6” grids. This was all done by mechanical pencil, and after constant erasing and re-drawing, when I was REALLY SURE of the accuracy, Iʼd apply ink to the line work.
This ink drawing was done with Rapidograph pens of varying widths, something Iʼd learned how to do in my cartography classes up at Humboldt State University in the 1980ʼs. My first job out of college was with Thomas Bros. Maps in Irvine, CA. In fact, at the time, we were still drawing street atlases by hand on light tables! All features on this map, along with the lettering, was done by hand. The next step, after the entire map was inked, was to scan the project at 300 dpi, thus converting my project into a JPEG ﬁle. Now Iʼd be able to color the trails, streams and roads on my laptop using an edition of Photoshop. Although I thought that the ink work was the most myopic part of the project, Iʼd soon discover that applying color to the project would be even more intense! While coloring, this process also gave me the chance to clean up a lot of my drawing. Some re-do’s were visible on the inked copy itself, while many more showed up at 200% scale on the Photoshop canvas (screen). A challenge that every cartographer encounters with any map is always what to leave in and what to leave out. Most contour lines were purposely omitted, with only index contours being drawn in at 200′ intervals. Special attention has been given to trail junctions and stream crossings. Eventually, after endless edits, I ﬁnally had copies printed in late November of 2014. As conditions in the environment change and trail realignments occur, I will make changes to the map image as needed. This current map is now in its’ third edition and available in either paper or pdf form. Itʼs my hope that you ﬁnd this edition of the “Chantry Flat – Mt. Wilson Trails” map an enjoyable addition to your outdoor experience.