GPS Limitations:

There are many different types of GPS receivers out there with differing capabilities. I created all of my data in a way that they can be used on most basic or older units. The GPS does not have to be able to display a map to benefit from this information. The following list reflects my desire to allow widest usability of the trail data.

Waypoints ==> Locations that are manually marked

• AKA "Points Of Interest" or POI
• Limit length to 8 characters that most newer units handle
• The first 2 to 4 letters are capitalized and are the same for all waypoints in a route to help group/identify them
• These first 2 to 4 letters are used as the map key
• Waypoint comments are limited to 16 characters
• There are many different waypoint symbol sets out there. These icon sets may vary even between versions of a GPS model
• Mapping these symbols between units is problematic
• Garmin 76Csx symbols are used in files I provide
• Use my GPXl8r application to translate them for other types of GPS units
• Lowrance units also have un-named points they refer to as "icons". You can't search for them, but they appear on the map

Routes ==> A group of locations that you visit in a set order

• • Originally I limited to 30 points per route for older Magellan compatibility
  • Most newer models handle 50 or more, but I now try to limit them just for documentation simplicity
  • Route names are limited to 13 characters in length
  • Routes can be traversed in either direction, although waypoint comments may not make sense if you do.

Tracks ==> Automatically recorded points that show where you've been or want to follow.

• AKA "Bread Crumbs" or "Trails"
• Track names are limited to 13 characters
• Limited to 250 points per track for earlier Garmin units. (Relaxed recently as most units now handle 500)
• On Garmin units, the active tracklog can hold more points than saved tracks. The track is automatically simplified when saved
• I've manually tweaked these track points to represent the actual travel as closely as possible
• Because of the point limitations, they do not follow every twist & turn in the trail, especially on long stretches where you don't have any path options
• The number of tracks that can be saved on a GPS or viewed at one time varies per GPS.

GPS Accuracy ==> Varies

• Depends on how well spread apart the "viewable" satellites are
• Virtually all units made since late 2005 are WAAS enabled, allowing as close as 10 foot accuracy
• WAAS is less usable the farther North you go in the US
• Typical estimated position error is in the range of 20-30 feet for most of the spots I mark
• Heavily wooded/steep areas typically have higher error potential

Mapped Track Accuracy ==> Varies

• As indicated above, it varies with the length of trail and how straight the trails are
• It is usually close enough to let you know which side of a street it was recorded on
• Larger discrepancies may show on trail sections where you don't have turn choices

Trail Organization:

Colorado Trails are split into several groups to help make working with them more manageable.  I initially split them based on their relationship to the confluence of the Platte River & Cherry Cr.

• CO_DS ==> Trails that are south of, or water drains ino the Platte River below the Cherry Cr confluence
• CO_DN ==> Trails that are north of or water drains into the Platte River above the Cherry Cr confluence
• CO_FN ==> Trails outside and north of metro area. Arbitrary cut: (Boulder/Brighton on to Ft Collins/Greeley)
• CO_CR ==> Trails in Douglas county south of the metro area e.g. Franktown, Castle Rock, Larkspur
• CO_CS ==> Trails in El Paso county
• CO_70  ==> Trails along I70 in the mountains

Trail Documentation:

I maintain both text and spreadsheet trail documentation for all of my mapped trails.  Documentation provides route statistics, waypoints, comments, notes and connecting trails.

Spreadsheet format ==> Microsoft Excel

• Separate sheet for overview and each trail
• Prints one page per trail
• Sheets hyperlinked to/from overview page and connecting trails

PDF format ==>

• PDF version of above spreadsheet - for those w/o excel or don't want to edit information
• Hyperlinks do not work here

HTML format ==>

• Separate files for overview and each trail (HTML version of spreadsheet)
• May print more than one page per sheet
•  Hyperlinks show but do not function

Map Key ==>

• I use a unique 2 to 4 character abbreviation for each track
• Key is used on maps to make them easier to read
• Key is used as the prefix for trail waypoint names
• Key is used as track & route name to keep things short & simple
• Key is color coded to track

Color Coding ==>

• Each trail has a color
• There are a limited number of colors I use for trails
• Available track and route colors vary by GPS and mapping or documentation software
• I try not to have two trails with the same color crossing
• Color printing can be problematic
• Some trail colors blend in with background on Topo and others on Satellite imagery
• Colors don't always print as they appear on a monitor
• Some GPS units allow you to set a color for specific tracks: I try to approximate key color. (Garmin, DeLorme & GPX format only of course, National Geographic is very limited)

GPS formats:

There are a lot of ways to store & transfer the data, I provide these:

GPS Exchange Format: .gpx

• This is the de facto standard for GPS information exchange, and is a form of XML
• Many software applications read/write this format, including some manufacturers (i.e.Garmin).

DeLorme Format:.an1, .anr & .pmo

• Used with their Topo USA & 3D Quad software
• .an1 stores waypoints, map symbols and track & trail items (also .an2 for Topo NA)
• .anr stores route data
• .pmo files are map overlays
• Since DeLorme started supporting .gpx, I no longer provide routes and tracks for this format
• I provide a draw layer for each zone of the tracks and waypoint files using PN20/40/60 symbols
• I now provide a map file that allows the entire trail network to be shown on PN20/40/60 by just copying it.

National Geographic: .tpo

• Another major consumer mapping contender, very easy to use
• Not as powerful as DeLorme, so it is much simpler to operate
• Since they started supporting .gpx, I only provide a file with all tracks for zone in it
• You can't output track data from this product

Google Earth: .kml or .kmz (compressed)

• Google Earth also reads .gpx files

You can use the free GPSbabel software to convert between these and many other formats.

My GPSxl8r software can help maintain track symbol usability between vendors.