Antioch Dunes National Wildlife Refuge. Saturday, Sept. 14. This is your chance to visit the only unit of the National Wildlife Refuge system in Contra Costa County. A 1-hour docent-led tour, 10-11 AM, will introduce us to the history of the only place on earth where one can see Lang’s Metalmark Butterfly. The butterfly requires Naked-stem Buckwheat for its entire life-cycle. Don’t be disappointed if we don’t see this butterfly. Don’t expect to see flowing sand dunes, though sand has been brought in from river dredging the last several years. After hearing the history, you will understand. May be hot; there is no shade; may be dusty walking along graded fire trails. Bring sun protection and water. Carpool from Sunvalley at 9 AM. From Hwy 4 in Antioch, exit north on A St. After about 1 mile, bend right onto Wilbur Ave. Turn left onto Fulton Shipyard Rd, and cross the railroad tracks. The entry gate is on the right. We will be guided by a refuge volunteer. Leader: Hugh Harvey, 925-935-2979. Category 2.