Surely I must be missing something...

...but I can seem to be able to plan a walking route. When I place all the way points on the map in BC, it calculates the route along roads and not the paths (trails) through fields, etc.

This is a pain, because a 15 mile walk ended up at 99.1 miles!

I want to plan it before I walk it!

Thanks.

Your map apparently only supports auto routing on roads. That is actually pretty normal.
Make a track instead. Zoom up the map and visually follow the paths and trails making enough trackpoints to maintain the shape of the trail with straight lines.
Much more work than routing but you will have the exact track you want.
Load it to your gps and you can navigate it or just visually follow the cursor and keep it over the breadcrumb trail of your previously made track.

Do not forget to press Start (depends on your gps) so you will have a record of where you actually walked for use next time.

Thanks Don,

That makes sense. I've got a Garmin 62st, if that makes too much difference?

I did try making a track, but I'm not sure how to upload it to my device, or how I get to it from there.

Oh well, let me have another look...

Thanks again.