Long before tourists arrived, a lone Englishwoman explored the vastness of what is now Rocky Mountain National Park.

Isabella Bird’s sojourn here came in the fall and early winter of 1873, not long after the mountain man and before the first pioneers built ranches here. She recorded her impressions in a book, A Lady’s Life in the Rocky Mountains, waxing poetic about the pristine landscape and describing the hardships she endured to explore it.

She observed: “The scenery up here is glorious, combining sublimity with beauty ... This is an upland valley of grass and flowers, of glades and sloping lawns, and clumps of pines artistically placed, and mountain sides densely pine clad ... and the mountains breaking into pinnacles of bold grey rock as they pierce the blue of the sky ... Deep, vast canyons, all trending westwards, lie in purple gloom.”

Bird explored the hard way: on horseback and on foot. Often alone.

Getting out of the car and onto the trails gives travelers the opportunity to enjoy nature up close.

Today’s visitors have it a little easier. Rocky Mountain National Park is bisected by Trail Ridge Road, a paved highway that whisks you from lake to beaver pond to trailhead.

But you won’t be alone. Rocky Mountain National Park gets about 3 million visitors a year — impressive, when you figure it doesn’t open to vehicles until late May or early June and often closes by mid-October, because snow blocks the roads.

National Geographic Adventure magazine named it one of America’s 10 best parks, calling it the “loftiest of all national parks,” and citing its accessibility for climbers. Climbing is indeed a world-class pursuit here, but most visitors do it from the seat of an SUV. The smart ones get out and explore.

Park ranger Kathy Brown has been doing just that since she was 11. In 1971, her parents brought her here, and she never forgot it. She became a park ranger with the intent of ending up here some day. That dream came true several years ago.

She has worked among the redwoods in California and the fossils at Florissant Fossil Beds, west of Colorado Springs, but nothing has captured her affection in the same way.

“Even when I was a kid, these mountains just got into my head and my heart, and I never can stay away from them,” she says. “I think it’s the combination of the mountains and the forests, and the wildlife that’s here.”

She loves that the park offers something for everyone, from wheelchair-bound visitors to serious hikers.

She calls Trail Ridge Road “a thread through the wilderness” that takes visitors from the park-like valleys that are home to the towns of Estes Park on the east and Grand Lake on the west to the alpine meadow at 12,000 feet (3,658 m).