The Olympia Master Gardners run a tour each year. My garden was on it one year. With the ticket purchased, you get the map. However, you must show the ticket to get into the garden on the day of the tour. Additional tickets are avaliable at each garden on the tour for last minute drop by folks. In Olympia, the ticket is the map printed on colored paper. There are people at each garden to check tickets and have a tally of how many people visited each garden.

I started the fall garden tour here in Wilmington, NC to benefit our local Arboretum. My garden is on the tour this year and I am again running the tour for this year. I am posting the website where we post information regarding the tour and found it is helpful to put the addressess of gardens on the tour with tickets being sold at each of the locations. Also our Arboretum which is pretty easy to find will sell tickets and tour goers can proceed with the map in the ticket from there. Most people can find one of the gardens and you can start with any garden where the tickets can be purchased by our garden hostesses/sitters. Maybe this info will help you.
When you get to this page, click on Art in the Gardens Poster to see our flyer,and the icon below it to see descriptions/photos of the gardens.
Pauline

Here is a link that might be useful: The Arboretum at Wilmington, NC