When President Barack Obama hiked Cadillac Mountain with his family in 2010, he made news not only because he was the first sitting president to visit Acadia National Park, but also because it’s uncommon to see African Americans and other minorities in this country’s national parks.

When Dr. Amanda McCoy, 29, and Dr. Kristin Alves, 28, both orthopedic residents at Harvard, took a trip to Acadia for the first time last month, they caught the sunrise over Cadillac and hiked the Beehive, Gorham, South Bubble and the Ladder Trail, but they also noticed the lack of diversity in other visitors to the park.

When Derrick Z. Jackson, Boston Globe columnist and co-author of a new book,

“Project Puffin”, and his wife honeymooned in Acadia more than 30 years ago, and went there on 2 other vacations, they enjoyed the challenging hikes and bird watching, but also lamented not seeing other African Americans on the trails.

“The thing my wife and I wish we would see more of” is African-American families “truly hiking, truly backpacking. That part is really, really white,” said Jackson, who’s also hit the trails in Yosemite, Death Valley, Great Smoky Mountains and other national parks, and written about them.

The lack of diversity in Acadia and elsewhere in the national park system, both in visitors and employees, has been a persistent issue, prompting studies to understand why, and initiatives to bring more people of color into the 59 national parks and nearly 350 other national park system units, from seashores to historic sites.

A 2011 report, “The National Park Service Comprehensive Survey of the American Public,” found African Americans the most “under-represented” visitor group, with Hispanic Americans not too far behind. The “2014 Best Places to Work in the Federal Government®” survey ranks the National Park Service 261st out of 314 agencies when it comes to support for diversity.

With the Centennial year coming up in 2016 for both Acadia and the National Park Service, and America’s population and workforce more diverse than ever, those aren’t exactly welcome statistics. Efforts to address the glaring disparity have stepped up.

This weekend, coinciding with National Trails Day(R), marks the 3rd annual African American National Parks Event, to encourage African Americans and other minorities to visit a national park unit, take a photo and post it on Facebook or other social media. Last month, the Acadia National Parks Community Facebook page posted a series of articles about the need to diversify both national park visitors and employees.

Why diversity matters in America’s national parks

Teresa Baker, founder of the African American National Parks Event, said that in the first 2 years, participation in the event doubled, from 1500 people visiting about 30 different units of the national park system, to 3000 people visiting 60 different units. This year, the event has expanded to include state parks, and now goes by the name African American Nature & Parks Experience.

Why is there a paucity of minorities, particularly African Americans, in national parks, Acadia or elsewhere?

Among the reasons, according to Baker: “The absence of park employees of color, the absence of park visitors of color, and the feeling of not being welcomed.”

Part of it may also be socioeconomic, and what you’re exposed to growing up. And part of it may have to do with the demographics of where most minorities live, and where many of the grand national parks are located.

Mount Desert Island, however, with its world-class Jackson Laboratory and connections to movers and shakers from New York to Boston to Hollywood, would presumably draw more minorities as they have made advances professionally in so many fields, and found more disposable income and time to visit a national park. For years, former Boston Celtics coach and player, K.C. Jones, ran a youth basketball camp through the Mount Desert Island YMCA, and helped raise funds through a golf tournament in Bar Harbor, and presumably would have visited Acadia.

Why does diversity in national parks matter? To Jackson and McCoy, it’s a social justice, environmental and public health issue.

“Rosa Parks and Martin Luther King, Jr., did not just fight for bus seats, lunch counters and school desegregation,” said Jackson, who’s written about civil rights, the environment, politics and other issues of the day in the Globe’s op-ed pages. The fight was to also allow African Americans the freedom to go to national parks and wildlife refuges, Jackson said, and to “take part in the environmental movement and preserve the outdoors.”

McCoy, the orthopedic resident, said “the rising obesity epidemic, particularly in African Americans, is an indicator of the low priority” placed on physical activity and exercise. In the two national parks she’s visited, McCoy said she’s seen only a few other African Americans, one man on South Bubble last month, and one family during a 3-day trip to the Grand Canyon.

And to the National Park Service, it matters to make the parks more relevant to an increasingly diverse population in this country, and perhaps at the same time broaden public support. NPS has a Web page about workforce diversity with links to pages about a cultural resources diversity initiative, employment information, gay and lesbian contributions to the NPS workforce and other related topics.

The history of minorities and “America’s Best Idea”

The lack of diversity in today’s national parks isn’t to say minorities haven’t played a role in the history, or shaped the present.

In the PBS documentary “The National Parks: America’s Best Idea,” Ken Burns and Dayton Duncan relayed the history of the parks not only through the well-known names of John Muir and Ansel Adams, but also through the stories of African Americans, Asian Americans and other members of underrepresented groups, both past and present.

Shelton Johnson, a Yosemite National Park ranger, shared his story of how he came to love national parks despite growing up in Detroit, and how he came to interpret the story of the Buffalo Soldiers, African American men who patrolled Yosemite, Yellowstone and Sequoia in the early years of national parks. He speaks often on the lack of minorities, particularly African Americans, in national parks.

QT Luong, also featured in the PBS documentary, as the first person to have photographed all of the national parks in large-format, told us in an e-mail, when asked about diversity in the national parks, “I think it is important because the parks belong to everybody.”

While he has seen Asian tourists visiting from abroad, and Asian Americans as well during his travels in the parks, he has not seen as many African American visitors.

Over time, the National Park Service’s mission has increasingly expanded to include more sites important to the history of underrepresented groups in this country.

For example, in 1992, the Manzanar War Relocation Center, where thousands of Japanese Americans were interned during World War II, was named a national historic site. And just last year, Secretary of the Interior Sally Jewell announced an initiative to identify landmarks important to lesbian, gay, bisexual, transgender and queer history.

The transcendence of connecting with nature

But while adding sites important to the history of minorities is one way for the National Park Service to be more relevant to diverse populations, for Globe columnist Jackson, it goes beyond that, to connecting people with nature.

“National parks…are truly mind expanding,” said Jackson, who credits his wife, Dr. Michelle Holmes, a Harvard epidemiologist who was a Girl Scout growing up, with turning him on to nature and national parks. “They expand the idea of the legacy, of what we leave behind for our children and grandchildren.”

Their youngest son, Tano, 24, achieved Eagle Scout status as a youth and has made nature an important part of his life, while their oldest, Omar, 29, has found his interests elsewhere.

Jackson will be visiting Bar Harbor in August, doing a reading and book-signing during The Waterbird Society meeting, with the recent publication of “Project Puffin: The Improbable Quest to Bring a Beloved Seabird Back to Egg Rock.” He first got to know his co-author, Stephen W. Kress, nearly 30 years ago, when he wrote about the ornithologist’s attempts to bring back puffins on islands off the coast of Maine. (NOTE: See sidebar about Amazon.com links on this site.)

On this trip to Bar Harbor, Jackson hopes to hike the trails of Acadia National Park again, and be one with nature.

But he also has a dream: “I want to be a park ranger when I retire.”