"routable" hiking trails?

[z_statman]

Not really sure as to reasoning: If you have the trail map loaded then you have the route? If you don't then create one in Google Earth or BaseMap or MapSource and load it to your GPSr. For GE, it is loaded as an overlay then enable)

My $.02

[RCinSTP]

popej, when you say "objects with multiple 'data' statements", do you mean that if I convert my polygons into OSM type polygons, the OSM type polygons have routing capability?
z_statman, I have the trail map loaded which has polyline trails between the lakes, but there are no polylines crossing the lakes from portage trail to portage trail.  For example, in the attached image, the red lines are a polyline layer, the yellow lines do not exist. The yellow lines represent canoe routes from one red line/portage trail to the next red line/portage trail. There are too many lakes and portage trails to hand draw all the yellow lines so that those line could be used with GPS routing features. I don't know anything about routing and I thought maybe there might be some way to automatically create a "route" from one red line/portage trail to the next but the route would need to stay on the lake polygons and not cut directly across the land. From the previous posts it sounds like it is not possible to make a route across a polygon and it's not possible to automatically generate polylines to represent the yellow lines in the image.

[popej]

popej, when you say "objects with multiple 'data' statements", do you mean that if I convert my polygons into OSM type polygons, the OSM type polygons have routing capability?

This note was about polish mp format, which is supported by cGPSmaper and mkgmap. If you use OSM format, then mkgmap should work better.

Objects with multiple 'data' statements are for example polygons with holes or polylines consisted of multiple separate pieces.

[RCinSTP]

popej, thanks for the clarification.  With GPSMapEdit when  you have polygons with holes, the holes don't display as transparent, they block the layer underneath, however, that is only is the screen display, the map will look correct on the GPS.

Per Konstantin Galichsky creator of GPSMapEdit "unfortunately holes may be visualized incorrectly in GPSMapEdit in some cases. However it does not affect the final view in GPSr."