From Cathlamet, take State Highway 409 south approximately 1.5 miles to West Birnie Slough Road on Puget Island. Turn west and proceed for approximately three-quarters of a mile to Crossdike Road Junction. Follow Crossdike Road approximately 1.5 miles to the junction with North Welcome Slough Road. The preserve lies along North Welcome Slough Road at this point for one-fifth of a mile.