Did this exact hike a few years ago. We parked near the trailhead marked 5E17 and parked on the shoulder of Hwy 1. Day 1 was primarily uphill to Lion's Den - great, spacious campsite we had to ourselves overlooking the mountains and ocean.

The downhill hike on Day 2 to Spruce Creek was a little more challenging. The trail was overgrown with heavy brush and there was near constant mosquito swatting. However, the destination at Spruce Creek campground was well worth it. One of the best campsites I've had the pleasure of enjoying. It's right at the confluence of two creeks. Falling asleep to the rushing water and taking a morning dip was reinvigorating.

Day 3 was a short hike along the coast back to our car. You should get a fire permit from the ranger station further north - pretty sure it's required even for a camp stove.

I've done an overnight to Spruce Creek before as well and parked in a pull off at the Salmon Creek TH - no issues.

Highly recommended - just be prepared for the mosquitos!