This thread will include camping spots along some of the Great American US Highways. The routes chosen are either long-distance routes, or routes that are long scenic routes. There are many, many US highways and I won't be including all of them. Also, bear in mind that some cities have parks that can accommodate tents or RV's but they aren't marked, and sometimes there isn't even a website.
US Highways:
US-1
US-2
US Highway 6
US Highway 12
US Highway 20
US Highway 30
US Highway 40 -- also known as The National Road
The Lincoln Highway -- Parts of this are now US-Highway 50, I-80 and others
US Highway 54
US-60
US Highway 61
US Highway 63
US Highway 66 -- also known Route 66
US Highway 83 (Laredo, Texas to Canadian Border)
US Highway 89 and US Highway 89-A
US-93
US Highway 95
US-101 (Actually on this page, just scroll down)
US-191
US Highway 212 -- Beartooth Scenic Byway
US-395
Great River Road, North to South
-------------------
First up -- US 101, which runs from near the Mexican border all the way north to Olympic National Park. This is a lovely alternative to the I-5 slab; my husband and I have done most of the length of it in California and Washington State.
Public Campgrounds along US-101, south to north (West Coast). Unless otherwise noted, all campgrounds are within 20 miles of the highway. There may be other campgrounds available; inquire locally.
CA:
Note: US-101 parallels/follows I-5 in most places from San Diego to the northern Los Angeles metropolis area. Also to note, CA state beaches fill quickly, especially in the summer anytime, and weekends throughout the year. Reservations are highly recommended if you actually want to have a space!
San Elijo State Beach, Solana Beach
South Carlsbad State Beach, Carlsbad
San Onofre State Beach, San Onofre
Note: Portions of this beach is a non-sanctioned nude beach.
San Clemente State Beach, San Clemente
Doheny State Park, Dana Point
Bolsa Chica State Beach, Orange County
Blue Jay Campground, Cleveland NF, Lake Elsinore
Note: This is about 25 miles east of the 101, and UP in the mountains. If beach camping isn't your thing, this is an alternative.
Malibu Creek State Park, Malibu
Note: Use CA-1, PCH, to access. There is no access from US-101.
Leo Carrillo State Beach
Note: Recently reopened after the Woolsey fire of 2018.
Point Mugu State Beach
McGrath State Beach
Emma Woods State Beach, Ventura
Carpinteria State Beach, Carpinteria
Los Prietas Campground,Los Padres NF, near Santa Barbara
Figueroa Campground, Los Padres NF, Santa Ynez
Note: BYOWater.
Refugio Campground, Goleta
El Capitan State Beach, Goleta
NOTE: Wagon Flat Campground, Los Padres NF, listed on many maps, has been permanently closed.
Pismo State Beach
Morro Bay State Beach
Navajo Flat Campground, Los Padres NF, Santa Margarita
Note: About 27 miles, but takes 45 minutes to get there. Very primitive, only 8 sites.
Pinnacles National Park
Note: The campground at Pinnacles is ONLY accessible from CA-25, on the eastern side of the park. This may make it very inconvenient. Included here only because it's a national park and may be a destination place.
Fremont Peak State Park, near San Juan Bautista
Note: Arrive before sundown, as the road up is winding, and the vehicle lights destroy astronomers' view of the heavens. This was a family favorite!
Half Moon Bay State Beach
Note: Access from the PCH, CA-1. About 15 miles, 30 minutes, from US-101.
Samuel P Taylor State Park, Lagunitas
Sonoma Coast State Park
Note: About 27 miles to the coast.
Sugarloaf Ridge State Park, Kenwood
Hendy Woods State Park, Philo
Note: About 28 miles from US-101.
MacKerricher State Park , Fort Bragg
Note: About 30 miles from the highway.
Standish-Hickey State Recreation Area
Richardson Grove State Park
Benbow Lake State Recreation Area, Garberville
Humboldt Redwoods State Park, Weott
Grizzly Creek Redwoods State Park, Carlotta
Note: If you're in a tent, request a site away from the highway. About 15 miles from US-101.
Sue-Meg State Park, Trinidad
Note: Formerly known as Patrick's Point State Park.
Redwood National Park
Prairie Creek Redwoods State Park, Orick
Del Norte Coast Redwoods State park, Crescent City
Jedediah Smith Redwoods State Park, Crescent City
Note: Another family favorite. It's always a joy to sleep among the redwoods!
Still to come, US-101 in OR and WA.