I believe the textbook way, at least with the old Traffic Cop implementation, was to create a field on the Contact/Lead objects for "Nurture Track" - you can then run a report off of this field in SFDC. For each nurture track, be sure to add a "Change Data Value" flow step to toggle this field.
New school way might be to create an Engagement Program which syncs to a SFDC Campaign. You can even go a level deeper and create different campaign member statuses and progression flows if your sales team needs details. The campaign object can be a related list on the Contact object, which'll show nurture track status to your sales team.
You can use both methods in conjunction for best results.