The trailhead is within Beacon Rock State Park which, as of 2012 requires a $10 single day Discover pass ($30 for an annual pass).
The gate is closed at the beginning of the road into the campground Monday through Thursday during the off-season. On Friday through Sunday it is open from 8:00 a.m. until dusk. From late spring to early fall the gate is left open at all times. If the gate is closed, park across the street in the visitors lot for Beacon Rock and walk up the campground road to the trailhead. This adds an additional 1/2 mile round trip to your trek.
There is a very nice picnic area near the trailhead including a nice size, relatively new playground, a pavilion and a dozen or so picnic tables. If this area is busy, there is another picnic area up the road a bit. Drive uphill about 0.2 mile and take the first left. Take that road to the end where you'll find a large pavilion and a whopping view of Beacon Rock.
Directions from Portland: Drive I-84 east to Exit 44 for Cascade Locks and Stevenson. After 0.4 miles, bear right for the Bridge of the Gods ($2 toll) and Stevenson. After driving over the bridge for 0.7 miles, turn left on Highway 14W for Vancouver and North Bonneville. Proceed 6.8 miles and make a sharp right at Beacon Rock where you see a stop sign. Drive uphill for 0.3 miles and pull into a parking area on your right.
Directions from Vancouver: From the I-205 merge with Exit 27, drive east on Highway 14 for 28.0 miles, passing through Camas and Washougal. Make a left at Beacon Rock for the campground, and drive uphill for 0.3 miles to pull into a parking area on your right.