First to go, as usual, is the Gleditsia triacanthos f.inermis that's the Thorney Honey Locust to you and I.

Located at the top end of Olympic Way the tree species would be typical to locations on the meridian (line of longitude) 100 degrees west of the Prime Meridian.  Roughly halfway across Canada and the USA.

Look out for the rest of the arboretum in the "Avenue of Champion Trees of the World" as they start to display their autumn colours over the coming months and see if you can guess which will be next to turn and which will be last to lose its leaves?