The Spring Wildflower Pilgrimage in the Great Smoky Mountains National Park will be held from April 21 to 25.

Now in its 60th year, it's the largest Wildflower Pilgrimage in the country. More than 1,000 attendees, called pilgrims, will descend on Gatlinburg, Tennessee, for wildflower and bird walks, lectures on composting and on attracting insect-eating birds and strenuous hikes. This five-day program attracts visitors from the Midwestern and Southern states and as far away as Colorado and Alaska. Started by the Gatlinburg Garden Club, the University of Tennessee, and the City of Gatlinburg, it is now managed by the Great Smoky Mountains Association.

Ken McFarland, a biology professor at the University of Tennessee, chooses the trails and leaders for the outdoor programs.

"We have lots of wildflower walks on both sides of the park (North Carolina and Tennessee). People come for at least two days and most do a wildflower and bird walk," he said.

Mr. McFarland personally will lead a hike on mosses and liverworts; he's been with the program since 1976. Other subjects include salamanders, insects, bears, and hogs

The highlight for Mr. McFarland is "talking to visitors and getting them engaged. They ask interesting questions. I like to have public understand and be more aware of the environment they live in."

Mr. McFarland explains that his challenge is finding people who are willing to come and are qualified to lead. The outdoor leaders volunteer and pay their own travel expenses. The program provides them with housing and meals.

"Leaders give pilgrims a different perspective and encourage them to take a scientific look at the environment in more depth," explained Mr. McFarland. "Walks are casual and slow-paced. We have two or three leaders per event, so they can engage with the public. We go rain or shine, so people should come prepared."

Indoor programs are also popular. This year, the headliner is A Theodore Roosevelt Salute to the Great Smoky Mountains. Joe Wiegand, who calls himself a 'reprisor' and not an impersonator, is "TR", known as our best conservation president. He'll tell stories of the early conservation movement and the growth of our national parks. Mr. Wiegand has even performed at the White House.

"I portray TR because his life and his stories speak to Americans today in a worthwhile way," said Mr. Wiegand. "TR’s dedication to family and country, his values and ideals, and his policies for conservation, a 'Square Deal' and a 'Speak Softly and Carry a Big Stick' foreign policy are very relevant to our current circumstances.

"I enjoy traveling this beautiful country and entertaining in the persona of TR, of whom his daughter Alice famously said: 'Father wanted to be the bride at every wedding, the corpse at every funeral and the baby at every christening.'"

Great Smoky Mountains National Park was created in 1934, long after TR died in 1919. During his tenure in the White House from 1901 to 1909, he designated 150 national forests, the first 51 federal bird reservations, five national parks, the first 18 national monuments, the first four national game preserves, and the first 21 reclamation projects. Altogether, in the seven-and-one-half years he was in office, he provided federal protection for almost 230 million acres, a land area equivalent to that of all the East Coast states from Maine to Florida.

Closer to Smokies history, Robin Goddard will give a performance on Ann Davis, considered the mother of the Smokies. Ms. Davis was elected to the Tennessee General Assembly in 1925 where she introduced a bill authorizing the state to purchase the first large piece of land for the park.

But let's not forget, it is the Wildflower Pilgrimage, after all. So what will the bloom be like on April 21?

"The last two years, we had spectacular wildflowers. In general, flowers are coming out a week earlier than they did 50 years ago," said Mr. McFarland, who studies the phenology of plants in the Smokies, the science dealing with the influence of climate on the recurrence of annual cycles such as flower blooms and bird migrations. "But this year, the cold winter will delay the bloom so they should be on schedule."

The details:

The Wildlife Pilgrimage runs from April 21 to April 25 (Wed to Sunday). Online registration is on now until April 11 at this site. Since each session has a limit, you should register as soon as you can.