I highly recommend as the previous posters said above Skinner Butte and Owen Rose Garden, They are both private, Skinner Butte has more a view that you are looking for Also, I know that you looking for area in the Eugene area but if you check out Mckenzie Orchards B&B Inn in Spring Field that is very private, The hotels policy is they allow outdoor canabis use in the smoking area. The view is beautiful and it’s a gorgouse inn located on the Mckenzie River and they serve wine and appetizers. Any of the choices would be the best bet. Enjoy (: