Guidelines for Establishing Zones

Zones tend to be assigned by drainage or trailhead. They are about 2-3 miles son a side, about the range of an FRS radio and the distance from which people can provide assistance. I designed the zones on the premise “how big of an area do I want to communicate with people. If I am on the Castle Peak approach, do I want to communicate with people on Mt Judah or Tahoe Donner? Zones reusing channels are a minimum of five miles apart. Each zone is assigned one of four colors corresponding to the channel assignment.

Link to add comments to document

  1. Backcountry zones should be defined on public lands. Private property and inholdings should be excluded.
  2. Boundaries should be defined, preferably using natural features (water, ridgelines). Man-made features should not be used, except for major highways (e.g. CA-89). Power lines may be used if no other options are available. Boundaries should be easily identifiable in winter conditions (for example, a summer hiking trail might not be easily identifiable once covered in several feet of snow).
  3. Backcountry zones should be contiguous.
  4. Backcountry zones should not include established commercial ski areas.
  5. Backcountry zones should have at least one established winter trailhead. Established means that parking is legal, the trailhead is plowed, and there is signage to identify the location. Non-established trailheads include pullouts along a highway or cul-de-sacs in residential streets.
  6. Zone names should be easily identifiable to users.
  7. Zones should consider typical usage and not require users to switch channels for most objectives (excluding long traverses). Corollary: Users should be able to use a single channel on a tour.
  8. Maximum size for a zone should be 3-5 miles. It is not a requirement to communicate from end to end of a zone.
  9. Zones should have some usage identified (see Strava global heatmap for winter activities). Areas with minimal usage identified may use the regional 5-30 channel.
  10. Signed trailheads should be established (legal, plowed in the winter, signed).
  11. Adjacent zones shall be assigned different channels (frequencies). Frequency assignments should not repeat within at least 5 miles.

Considerations

Why would we make a zone smaller?

  • Too many people in a zone.
  • There is the possibility of communication, but the people are too far away to help.
  • There is a natural boundary like I-80 or CA-88.

Why would we make a zone larger?

  • Simplicity.
  • Typical usage would be within a single zone.

Link to add comments to Google Doc.

CalTopo zones map.

GeoJSON to import to other map programs