Notations such as “(Hike 106)” refer to hikes in my book Day Hiking: Oregon Coast.
Updated 9/25/14 with new details about the trail south of Crook Point: From the Rogue River’s south jetty, head south on the beach. At 2 miles wade the outlet of Hunter Creek. Continue another 3 miles to the base of Cape Sebastian and look for a trailhead post and trail angling up off the beach 0.3 mile before the beach ends. This trail (north side of Cape Sebastian) is little used, poorly marked when last I hiked it, and hard to follow in places, but it beats the highway shoulder.
Here's my best shot at trail directions to the top of Cape Sebastian (in general, if you bear right at trail junctions you will stay on the trail and stay off US 101).
Start up the trail and, after 1 mile, turn right at what should be a signed trail junction, then go right again immediately. The trail descends for 0.7 mile, then ascends about 0.2 mile to an unmarked junction. Go right (down). The trail levels out, passing two OCT posts in a row; through this section basically stay on the main double-track trail/old road. It may be extremely overgrown (a crew came through and wacked back the salal two days after I hacked my way through in mid-July). At 3.2 miles (from the beach), the trail emerges into a grassy viewpoint (nice bivouac spot if you have water?); re-enter the forest by the trail post and go up a very, very steep, narrow trail through a lovely, airy forest for 0.8 mile to the north parking lot at the top of the cape (9.3 miles). From here it's easy; follow the park road north 0.5 mile to the south parking area. From here, follow the asphalt trail west, then pick up the forest path leading down the south side 2.5 miles to the beach (Hike 106); watch for poison oak toward the end of the trail (12.3 miles).
Continue down the beach 4.6 miles, wading the Pistol River, all the way to the beach's end at Crook Point. Here, scramble across the driftwood pile marking the end of Sand Creek, below an OCT post in the dunes. Follow it up and across the dunes. Beach grass overhangs the trail through here, obscuring the route; just follow your feet and occasional white-topped trail posts painted with black Us, or horseshoes (the trail is also used by horseback riders). At 0.4 enter an open bowl of sand; cross it and rejoin the trail at the wooden “Coast Trail” sign. From here the trail climbs and contours around hillside ravines, in and out of cool spruce forest and open piney dunes, mostly on soft sand. At 0.75 you’ll reach a junction with Lola Lake Loop; continue straight to reach the trail’s end at US 101 in 0.25 mile, a total of 1 mile from the beach (or detour around the Lola Lake Look for a view of what is, in summer, a grassy depression and adding about 0.4 mile to your walk).
Now it’s back to the highway shoulder southbound for 2.1 miles until the OCT resumes at Sam Boardman State Scenic Corridor (details below). The OCT winds a total of about 20 scenic miles on trail and beach between the highway and this dramatic coastline along a 12-mile (highway miles) corridor. It's extremely scenic, but be aware that it is constantly going up or down (so not an easy 20 miles). There is NO potable water available along the trail, and the only (vault) toilets are at Arch Rock Point Picnic Area, Whaleshead Day Use Area, and Lone Ranch Beach at the very end. No camping is allowed in the park or on the beach (though some hikers seem to have managed an unobtrusive bivouac).
To find the north end of the OCT through Boardman, look for a blue OCT-signed trail post a few steps north of highway milepost 343. Trail drops down and up and returns to highway in about 0.4 miles at a highway sign for Arch Rock Butte. It resumes and drops down the hillside toward the beach (you'll see Whiskey Creek in a concrete flume on your right); the trail is very steep and slumping downhill in places. It crosses a couple of creeks on footbridges before heading back uphill to another trail post just downhill from another highway turnout just south of the Sam Boardman Corridor entrance sign. Stay on the trail heading south, just below the highway, until it leads to the parking area at Arch Rock Point picnic area (about 2.2 mile from resumption of OCT in the park). Follow the OCT trail 0.3 mile to the Spruce Island Viewpoint trailhead (Hike 108), then another 0.75 to where it meets the trail from the highway down to Secret Beach (Hike 109). Secret Beach is a lovely spot (it looks as though through-hikers sometimes bivouac just above the beach here. At any rate, it's a good place to end this penultimate OCT post (21.6).