A day-use fee of $5 is required at the trailheads listed below. Or buy a $30 Northwest Forest Pass at the Oregon Dunes NRA Visitor Center in Reedsport.
From the Stagecoach Trailhead (look for the 'Siltcoos Recreation Area' sign 7 miles south of Florence), three short trails along a river and wetlands afford good wildlife viewing. One of these, the Waxmyrtle Trail, winds to the beach for 1.5 miles along the Siltcoos River, where herons, deer and waterfowl can be seen. Other trails lead to a freshwater lagoon or up to a forested vista point.
At Carter Lake Campground, 12 miles north of Reedsport, the Taylor Dunes Trail leads a half-mile to a viewing area. You can hike beyond here through dunes to meet the Carter Dunes Trail and head to the beach (3 miles round-trip). The Oregon Dunes Day Use Area, about 2 miles south, has good viewing platforms and serves as a trailhead for a 2-mile round-trip hike to the beach.
The challenging, 6-mile Tahkenitch Dunes Trail loop starts from Tahkenitch Campground, 8 miles north of Reedsport. You'll reach the beach in about 2 miles, then walk south about a mile to signs for the Threemile Lake Trail, which returns to the campground via a freshwater lake and deep forests.
For the area's biggest dunes (including the tallest at 500ft), take the John Dellenbeck Trail, 10.5 miles south of Reedsport, which leads out across a wilderness of massive sand peaks before reaching the beach. The round-trip hike is 6 miles and involves some tough dune climbing, though there's a 1-mile interpretive loop on packed gravel if you just want to take a look.