I'd like to save my tracks on my 66st but not have them show up every time I return to that area to create another track. If I archive them instead will that hide the old tracks from automatically showing?
On my 62s on the track manager page, select a track, press 'Enter' button then select 'Hide on map' or 'Show on map'. There's probably a similar option on your unit. I've never used the archive function - I transfer my saved tracks to my PC and delete them from the GPS unit.
Just to update, seems that if I do keep the old track in 'archive', it won't show on the new hike. But when I download it into "Basecamp" both tracks will show up. That's fine for me.