Shore Acres State Park is a wonderful park and good to visit any time of year https://shoreacres.net/wp-content/uploads/2015/07/Garden-Map-Card-web.pdf). It is located near the city of Coos Bay. The area and the parks found there are certainly worth seeing.
If you want to see the whole park and enjoy the ocean, park happenings and especially the fantastic gardens, then spring, summer or fall have much to offer. Each of the seasons bring forth wonderful floral display, so there are colors to enjoy year-round. This scene of a pond display in the gardens was made in the fall.