AUSTIN, Texas — Fifty years ago, Americans didn’t need jingles (“See the USA in your Chevrolet”), slogans (“America at its best”) or advertising campaigns (“See America first”) to pack up the family station wagon and head into the great outdoors. The availability of middle-class leisure, large cars and cheap gas, along with an interstate system that smoothed the way, meant that any spot in the continental U.S. was increasingly accessible to a large number of Americans.

Add another motivating factor: Lady Bird Johnson.

The late first lady, whose centennial is celebrated this year, teamed with Secretary of the Interior Stewart Udall to stage tours of the country’s most camera-ready landscapes, sometimes giving a timely push to win them official designations as parks or wilderness areas.

In honor of her centennial, why not plan a journey to the high points of Lady Bird’s outdoor travel in her home state of Texas, before, during and after the Johnson presidency?

Start at the Lady Bird Johnson Wildflower Center in Austin. The immersion in nature starts in the parking lot and continues through winding trails, cosseted courtyard and fresh exhibitions. Don’t skip the Mollie Steves Zachry Texas Arboretum and come back later when the new children’s garden opens.

Next, drive 90 minutes west to the Lyndon B. Johnson National Historical Park in Stonewall and Johnson City. Much of the historical material is indoors – especially at the newly opened-to-the-public Texas White House – but LBJ and Lady Bird insisted on leaving behind a working ranch.

Do what Lady Bird would do: Behold the fields flecked with scissor-tailed flycatchers and meadowlarks.

It’s a short trip – 30 minutes, more or less – from the ranch to Enchanted Rock State Natural Area north of Fredericksburg. Lady Bird helped protect this revered granite outcropping and put it under state protection. You don’t have to be rock climber to reach the summit and take in a grand expanse of the Llano Uplift, which inspired Comanches, German settlers and countless campers.

Then take a step back in time, heading far northeast to Lady Bird’s birthplace, Karnack, and the nearby Caddo Lake State Park. It’s a seven-hour ride over the plains and through the pine forest.

Lady Bird often said her love of nature was stoked during childhood walks through the dense woodlands of East Texas. Located on the Texas-Louisiana border, the lake is surrounded by one of the world’s largest cypress forests.

It would take almost 12 hours to reach the next destination: Fort Davis National Historic Site and, around a bend, Davis Mountains State Park. In the arid sunlight, the fort’s military structures – left over from the 19th-century Indian Wars – are remarkably well-preserved. Lady Bird promoted this attraction as well as the park in a fold in the Davis Mountains that offers serious hiking and wildlife. Loop through the rest of the highlands along the Texas 118 and 166 highways.

It’s just over three hours to the next stop: Guadalupe Mountains National Park. It was on Lady Bird’s watch in the 1960s that Congress approved the park with Texas’ highest peak that was eventually dedicated in 1972. Don’t miss rugged McKittrick Canyon, but be careful. Temperature variations are extreme, and much of the park is quite remote.

Another five hours, and you can make Big Bend National Park, a vast agglomeration of steep mountains, broad desert floors and narrow canyons along the Rio Grande. News cameras doted on Lady Bird as she rafted these waters. You’ll be warned here, too, that this is another place to respect on peril of your life. Always let rangers know where you are headed and take along lots of water. You can drive all day here and not see a soul. Don’t hike without careful plans.

One last long leg: It would take well over nine hours to reach Padre Island National Seashore on the Gulf Coast. Here, giant dunes tower over tidal sands and camping can be quite an adventure. Don’t head too far down the beach without a four-wheel drive vehicle. Birds and fish abound.

When you return to Austin, stroll around Lady Bird Lake on the Roy and Ann Butler Hike and Bike Trail. The first lady originally conceived the lakeside makeover with the Butlers, who put the concept into action.

As you walk for miles in this landscaped paradise, meditate on the fact that the green movement can trace a thread of its conceptual and emotional origins to the road trips of Lady Bird Johnson.