McKinleyville - (5.5 miles; one-way) - Hammond Coastal Trail

Mad River Road (S) / Clam Beach (N)
Arcata/McKinleyville, California 95519
Northern Humboldt

This beautiful walking/running/biking trail runs from Arcata to McKinleyville or the other way around for a distance of 5.5 miles each way.  The south trailhead is at a bridge along Mad River Road (see map). The northern trailhead is at Clam Beach.  If you're looking for something shorter, the trail has multiple places you can jump in, Hiller Park being a popular place, so you can make your adventure any length you want. 
The southern part of the trail takes you through the countryside of northern Arcata and into Mckinleyville.  Once you get through the Hiller Park area, the scenery becomes more coastal. The northern trailhead sits right near the ocean at Clam Beach so you really get to pick the scenery you want by choosing the trailhead you decide to start from.
Distance:  5.5 miles (one-way) 
Degree of Difficulty: Easy
Dogs: Yes, on leash.  Please pick up after your dogs.
Camping:  Yes - at Clam Beach 
How to get there:
Arcata Trailhead;  Giuntoli Lane exit from 101 and head west on Janes Road.  Turn right on Upper Bay Road and then make a right on Mad River Road and follow it until you see the bridge/trailhead. 
Mckinleyville Trailhead; take the North Central Avenue exit from Highway 101 and head toward the beach. You'll find the parking lot near the south campground. 
More info:
Don't leave valuables in your car. 
Other things to do in the area: 
Up the road in Trinidad, find Trinidad Head which is nice hike that gives you incredible views of Trinidad State Beach and the amazing NorCal coastline.  In Arcata, the Arcata Community Forest and the Arcata Marsh are both great places to find some relaxing trails in stunning environments.
*Click on the photos below to enlarge them