“Mount Diablo, Los Vaqueros & Surrounding Parks,
Featuring the Diablo Trail”

Save Mount Diablo’s New Regional Recreation Map
By Seth Adams & John Kelly

Save Mount Diablo has produced the first regional trail map of the Diablo region including Mt. Diablo State Park, Los Vaqueros and thirty-six other parks and preserves.  The map is full color, double-sided, waterproof and tearproof.  Our volunteer map committee walked hundred of miles of trails with Global Positioning Systems (GPS) units and worked for two years to document all of Diablo’s parks and trails for the first time in the most accurate Diablo map ever created. 

Funding was provided by REI in two grants totaling $9,000.  This map is the first to give a sense of the full scale of land preservation around Mount Diablo, to spotlight the 30-mile Diablo Trail and to show all of the regional trail connections between the various state, regional and local parks. 

Elements of the Mount Diablo Map

When SMD was formed in 1971 there was just one park on the mountain measuring 6,788 acres (about 10.5 square miles).  In order to reach the park you had two choices-drive halfway up the mountain on North Gate or South Gate Roads before entering the Park gates.  Public and protected lands around Mt. Diablo State Park have increased significantly since that time and SMD’s map seeks to show all of these lands.

The map covers 250,000 acres (390 square miles), of which over 90,000 acres are public or protected (141 square miles versus 1971’s 10.5 square miles).  Public trails cover 520 miles, including 50 miles of paved trails (for example, Iron Horse, Contra Costa & Ygnacio Canal trails). An additional 400 miles of private fire roads are shown in the map background.  There are over 3,000 labeled features.  These features include 900 elevation points; a hundred creeks; fifty lakes and ponds; 800 mileage markers for each trail segment; 80 ridges, canyons and valleys; and 130 cultural points.  A hundred trail heads, parking lots and other access points are assembled for the first time.

The 30-Mile Diablo Trail & the 60-Mile Diablo Grand Loop

The 30-mile Diablo Trail is shown for the first time on this map.  In 1993, SMD proposed the multi-use Diablo Trail to showcase the regional cooperation that has been preserving lands across Mount Diablo from Walnut Creek to Brentwood and Livermore.   

The Trail is an important focus for recreation opportunities on the map, as well as a unifying element in SMD’s conservation efforts.  The title, narrative text boxes, locator map, yellow highlight, and an elevation profile aim to emphasize the Trail and the proposal for the “Diablo Grand Loop” north from either end of the Diablo Trail.

The map also includes dozens of other unique features.  For example it’s the first map to show the new Los Meganos State Historic Park, Vasco Caves Reg. Preserve and the Los Vaqueros watershed in detail. 

We didn’t intend to include all of the detail of specific larger scale maps, but the map makes a huge attempt.    For example, Shell Ridge is crowded with place names, some of which aren’t included on the map.  In other cases, historic geographic names have been resurrected.  A 1915 Mt. Diablo map for example, before the State Park was created, first named Rock City’s “Madrone Canyon” but more recent maps have lost this place name.  We’ve resurrected it.

Why Create a New Map? GPS

Although numerous maps have detailed some of the parks in the East Bay, SMD’s map presents all of these elements in a unified design, taking advantage of new cartographic technologies.  Historically, trails were physically drawn onto a base topographic map.  In drawn maps, features are often moved around to make room for labels and other information.  This map was surveyed by walking trails using GPS units and then assembling and collapsing hundreds of layers and a vast database of information with ArcInfo GIS, Adobe Photoshop and Illustrator software.  Not only will this information benefit future map editions, it also allowed automation in trail segment mileages and trail intersection elevations.

Further, the map is an educational tool.  SMD wanted the map to celebrate protected lands and to highlight private land still in need of preservation.  On the map, the public can see both the accomplishments of the coalition of agencies and groups working in the East Bay and the work that lays ahead. 

The map will be a tremendous resource for all types of recreational users.  They’re among our biggest allies and we know that getting people onto the land will help increase their interest in conservation.

The Map Committee

The mapmaking procedure is equal parts science, art, sweat and love.  John Kelly, our volunteer cartographer, is responsible for most of the map’s design features.  He devoted thousands of hours into making the map amazingly detailed, yet easy to use. He scanned dozens of other maps to glean information, and corrected the map at minute detail with 400 aerial photos.  He labored over decisions from label and icon design, to color choices, to identifying gaps in information for others to provide.

Every trail and point of interest was positioned according to aerial photographs (2005, USDA, 1 meter resolution), and most were also field-verified by GPS. Elevation values and shading were created from USGS data using both analytic techniques and subjective artistry.

Huge thanks are due to our volunteer map committee which met monthly during the two years it took to create this map.  The committee included John Kelly, Don de Fremery, Ken Dyleski, Scott Hein, Michael McCormack, Kate McKillop, and Dave Husted and was staffed by Seth Adams, SMD’s Director of Land Programs.  Chris Ritter and Aaron Steinstra of The Focal Point LLC gave valuable pro bono feedback on graphic presentation.

Committee members tirelessly verified features, each person providing unique expertise in areas of history, first-hand field knowledge, and the harnessing of cartographic and design software.

Drafts of the map were sent to various agencies for their suggestions and corrections, including Contra Costa Water District, East Bay Regional Park District, Mt. Diablo State Park, the Mt. Diablo Interpretive Association, the City of Walnut Creek Open Space system, and the Walnut Creek Open Space Foundation. 

Louis Jaffe, Beth Stone and Roger Epperson provided significant help, and Roslyn Bullas of Wilderness Press provided advice on pricing and distribution.  SMD volunteer Christine Odom wrote two successful grant applications.  Special thanks to Doug Tracey of REI-Concord for his help.

Two Maps in One

Generally, recreational users are most familiar with Mt. Diablo’s west side and the upper elevations of Mt. Diablo State Park, where acquisition began in 1931, but most preserved land is actually east of Diablo’s summit, acquired over the past two decades.  The map brings these new areas to the public’s attention.

Mt. Diablo’s two biggest public parks are Mt. Diablo State Park and the Los Vaqueros watershed, located diagonally from each other across Riggs Canyon, Highland and Morgan Territory Ridges.  We could have easily justified two maps but instead made this one double-sided and overlapping, in part to make it more affordable, each side focusing on one of these two largest parks.  The west “Mt. Diablo State Park” side includes more detail, given its long public history, and most of the length of the Diablo Trail.  The east “Los Vaqueros” side represents our determination to extend public lands all the way to Bethany Reservoir and the Central Valley.

Protected Vs. Accessible

Areas on the map include shading and labels that indicate “no public access.”  Acquisition efforts are ongoing and much of the land depicted has been protected recently.  It may take years to assemble parcels for a park and then more time for cleanup, and construction of public facilities and trails, before access is allowed.  Some of these areas will be open in the future while others are protected for sensitive resources or by conservation easements that do not include public access.  We felt it was important to show all of what was protected as well as what is accessible.

For example, land purchases at both Los Vaqueros and Round Valley Regional Preserve began in 1988 but it wasn’t until 1998 that they were opened to the public, while Los Meganos State Historic Park (Cowell Ranch) is just now undergoing the General Plan process that precedes access. 

The map also indicates potential.  For example, the Concord Naval Weapons Station is owned by the public but undergoing a reuse planning process which will decide which areas are protected and which might be developed.  The map easily demonstrates the short distances from the Weapons Station to Clayton Open Space and to Black Diamond Mines Regional Preserve.

A Vast Expansion of Recreational Opportunities

Despite limited access areas, the map highlights the vast expansion of recreational opportunities in the area.  The increase from two entrances and Mt. Diablo State Park’s 10.5 square miles in 1970 to more than one hundred access points, 520 miles of public trail and 141 square miles of preserved land today is certainly a note-worthy achievement.

SMD invites everyone to enjoy the Diablo Map and to get to know the outstanding collection of public natural lands in the Mount Diablo and Los Vaqueros areas.

Map Design Elements: A Tour of Save Mount Diablo’s New Regional Recreation Map
By Seth Adams & John Kelly

SMD’s new Diablo Map challenged the entire map committee with the monumental task of presenting a large amount of information accurately and in a user-friendly format.  Over two years time, numerous decisions were made in terms of the colors, the design features, and the visual hierarchy found on the map.  Here is a behind-the-scenes look at some of the design and content issues encountered in the mapping process that will give you a deeper appreciation of the volunteer map committee’s work.    

Diablo Map Design Features

The detail we wanted to provide and the vast extents we wanted to cover combined to make this map an extreme cartographic challenge. The spatial extent of the area was fixed; the feature density demanded a scale at least this large.  This is not a spacious national park or remote forest—the west side in particular is very busy with people, features to accommodate them, and related geographic names.

Showing less land was unacceptable and a smaller scale would have meant eliminating detail. The small fonts and the large paper size (34 by 40 inches and double-sided) were the compromises that enabled us to provide such breadth and depth of information. 

By making regional parks a darker green we helped define different agencies’ lands, signaling changes in management and regulation.  We attempted to minimize the prominence of man-made features and labels at a distant glance so that they wouldn't compete with the presentation of the natural environment and the preserved areas.

Regional Trails that connect with parks, schools, libraries, BART stations, etc. are all included (even SMD’s office location).  Text includes some of the most commonly sought information about the mountain—a brief history, why it’s special, how it was formed, how it got its name—and about the Diablo Trail and Save Mount Diablo.

Because terrain undulations are such a defining part of the area, we included elevations of most trail junctions as well as major and minor peaks.  There are over 3,000 labels. To keep the map from being covered in label ink, and because most of these names and numbers only need to be readable when the user focuses on a narrow area, most of the text is small and fairly light.

Although we would have liked to have shown all of the roads and freeways necessary to reach trailheads, we compromised by including a smaller locator map with these major roads.  In the opposite direction, two heavily used, complicated areas within Mt. Diablo State Park, “the Junction” where North Gate and South Gate Roads meet and “Rock City,” are expanded to show greater detail. 

Given more than a dozen managing agencies each with different missions and public regulations it’s also difficult to adequately include all of the “rules.”  Nonetheless we have attempted a unified set of guiding regulations.

Contours, Coordinates & Hypsometric Gradients

We chose 100’ contour intervals, with an index contour every 500', vastly wider than USGS maps of 20' or 40' contours. Since the area is quite hilly, the contours are still spaced closely enough to illustrate terrain shapes. Our hope is that the relief shading and spot elevations (trail junctions and peaks) aid in defining terrain shapes.

The primary navigation coordinates are the UTM (Zone 10) numbers along the edges. The Universal Transverse Mercator (UTM) coordinate system is a grid-based method of specifying locations on the Earth’s surface. It differs from the traditional use of latitude and longitude; the UTM system is not a single map projection. The system instead employs a series of sixty zones, each based on a specifically defined secant Transverse Mercator projection.  We used kilometers instead of meters to avoid unnecessary zeros. The A,B,C...1,2,3... grid labels the boxes instead of the lines, for less precise, quicker reference (for a wider audience).

Filled, open space polygons (even though transparent) mask elevation shading and tints. We considered an inner glow effect on the boundaries, but we wanted the display of preserved acreage to be loud and clear.  Unnatural, yuletide (red on green) trails-on-parks colors?  We wanted the trails to really stand out. For the same reason, roads and highways are intended to be clear, but somewhat in the background of the visual hierarchy. Our deep apologies to the people who are red-green color-blind or color-deficient; we will try to find a better color pairing in the next version.

Elevation colors? It is very difficult to please everyone in this subjective amalgam of many parameters. Additionally, the use of colored polygons for parks adds another factor to the feel. (Whether to block out the hypsometric gradient with the park color or have it change the park color was a point of discussion, for example.)

In theory, elevation tinting hints at vegetation changes due to elevation-dependent temperature and precipitation. Over an area as narrow (both vertically and horizontally) as this one, color changes much more dramatically with the seasons than with distance. Although the entire area is green in the spring, for much of the year it is dry and golden (the balance between yellow and brown—and sometimes the black of fires—is subtle); thus the general yellow color in most of the non-park area. As with hypsometric tints that include glaciated mountains, this spectrum goes to white at the top. While the higher elevations on this map do not have snow or ice for about 360 days of the year, we justify the white with those few days of snow-dusted peaks.

Blocking out versus multiplying park color with elevation color: our volunteer cartographer John Kelly opted to multiply.  He felt the effect on the park color was subtle enough to not interrupt the cohesion of its symbology, but just noticeable enough to provide another indication of the elevation change within the parks. Perhaps any effect of the latter is too subtle, but he wanted to err in the direction of the other option (full knock out of the elevation color).

Compass Rose & Scale

The compass rose (which depicts North-South-East-West direction) is somewhat larger than necessary.  North arrows and compass roses are often overused and abused; they can be a simple line with an arrowhead (or two lines, if magnetic declination needs to be shown) or be left out entirely (if north is directed to the top of the page). For this map it is important to trail travelers that we show magnetic north, and true north is very slightly off of grid north (UTM).  There is a subtle, whimsical hint here that Kelly is a serious cyclist.

The scale bar is plain. Lacking a justifiable flourish to this linear necessity, this design was Kelly’s ode to minimalism. He thought a bar of alternating black and white filled rectangles was too loud and understood the fondness for the USGS (et al.) scale bar with intermediate marks and alternating centerlines. But he felt subdivisions and extensions (making zero not at the left end) can take away from the at-a-glance use of the scale bar, and the subdivisions can be estimated mentally. The trail distance labels and 1km grid throughout the map provide considerable scale reference.

“Mount Diablo, Los Vaqueros & Surrounding Parks, Featuring the Diablo Trail,” SMD’s new regional recreation map is full color, double-sided, 34” x 40”, waterproof and tearproof.  It is available at the SMD office for $9.95 plus tax, or by mail for an additional $3.55 in tax, postage and handling (total $13.50). Visit our office, call in, or mail or fax your order using the order form.  Map is also available at REI Store in Concord, 1975 Diamond Boulevard and Forward Motion Stores in Walnut Creek, 1352 Locust Str. or in Danville, 432 Hartz Ave.

Map Order Form

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