For obvious reasons, Yellowstone National Park — dazzling in natural wonder and wildlife, and sprawling over parts of Montana, Idaho and Wyoming — has been the subject of dozens of books reflecting its majesty through photography, nonfiction and even novels.

It's hard to imagine there's anything new left to say about it.

But in their powerful and indelible new "People of Yellowstone," photographer Steve Horan and Mystic writer Ruth W. Crocker explore the nation's first national park from an intriguing perspective — through the eyes, hands, hearts and minds of the folks whose lives, careers and passions intertwine there. Comprising 87 black and white portraits and facing-page subject essays, "People of Yellowstone" works not only as a fascinating study of distinct individuals, but their stories gradually segue into a "bigger picture" canvas that captures Yellowstone's almost mystical power of seduction.

Horan, whose gallery exhibitions have appeared across the U.S. and his native Canada, spent five years photographing the folks in the book. He first visited Yellowstone in 1984 and, over time, realized that the beauty and wildness of the park was matched by the human element surrounding the natural phenomenon. It was, he says, a revelation that could spark a good book. But, while he initially thought it would take two years, he also learned that life at Yellowstone is very seasonal and complex. Not everyone works or lives in a year-round context and, by definition, the array of jobs and lifestyle opportunities implies that people are not necessarily easy to pin down in terms of time or location.

"These are people who are extremely busy," Horan says, "and the amount of work going into researching, scheduling, brainstorming for photo-shoot ideas and locations, and actually then doing the shoot, was different for each subject. It quickly became much bigger and time-consuming than I'd anticipated."

Too, the people Horan photographed are multi-faceted, to say the least. Flipping through the book, for example, subjects are identified by the components of their biographies. These might range from "U.S. magistrate judge in Mammoth Hot Springs" and "Backcountry ranger, wildlife advocate, citizen scientist" to "Former director of Yellowstone Center for Resources, fishery biologist" and "Artist, wrangler, fire guard, pilot."

It was an astonishing collection of lively, e'er curious and committed individuals for Crocker, who wrote the profile essays and came into the project by accident. Though she lives 2,300 miles away from Yellowstone, Crocker was more than casually familiar with the park. Her brother, Bob Whipple, is a long-time Park Ranger at Yellowstone.

"I'd been out there to visit many times, and the park is lovely and beautiful — but at first it didn't hit me in the same way that it did Bob," Crockett says, speaking earlier this week from her home. "Then the book opportunity came along."

That was in 2013. Horan was shooting pictures of Whipple for the book and happened to mention that the original writer had just quit. Whipple responded that Ruth was an author and that Horan should get in touch. Her essays and nonfiction pieces had appeared in such publications as Gettysburg Review and The Saturday Evening Post, and her memoir, "Those Who Remain: Remembrance and Reunion After the War," was about to be published.

Horan called Crocker to explain his idea and see if she was interested in writing the pieces to go along with his images. Of the phone conversation, Horan says, "We spoke for about an hour and I did most of the talking, trying to convince Ruth about the merits of the project. That was when Ruth was releasing her book, so I knew it was tough (asking her for) hundreds of hours of her valuable time to write stories about people she'd never met."

At first, Crocker says she found the whole idea "nebulous and amorphous. There were originally photos of 120 people, and I'd have to interview them all. I liked the idea of having a new project lined up, but there were problems, not the least of which was that I lived in Connecticut. Plus, most of the people in the book work in the park and their jobs might be seasonal. And when they ARE working, it's pretty much nonstop."

Nonetheless, Crocker was impressed. Horan's enthusiasm and commitment resonated in a significant way. Along with her brother's passion for the park, Crocker decided it was enough to sign on. "I told Steve that I had to finish and publicize the memoir but, that if he was willing to put up with my schedule, we could do it."

Logistically, Crocker had to do most of the interviews via phone or email, though she did make trips to the park. A bigger challenge was in determining how to boil the lives of the portrait subjects down to about 350 words each, which was the space allowed by formatting.

"I'll tell you, when I saw the original list and the actual photos, which were so revealing and beautifully composed, I thought it would be impossible," Crocker says. "So many of these people have such amazing lives. People have been attacked by bears or they've overcome amazing hardships like war injuries. Some just showed up at Yellowstone on a bus and got off and said, 'This is it. I'm staying' or maybe they attended a wedding at Yellowstone and there's something about the place that grabbed them. Yellowstone has a very spiritual effect."

Over time, Yellowstone worked its magic on Crocker, as well. She describes the sheer overwhelming variety of the geography — of the geothermal springs or the mountains or towns where elk are considered sacred and run through the streets. "Meeting and learning about all these people, in those spectacular settings, Yellowstone grew on me, and so did the individuals I interviewed. I'm so grateful Steve called me."

It's a sentiment Horan shares: "At first I wasn't sure I could talk Ruth into this, but I'm lucky she agreed. She's a special spirit and a friend to everyone she meets. And she captured the spirit and the personality of the people in the book perfectly."

Though "People of Yellowstone" was originally going to come out from a different publisher, it's now a product of Crocker's own "Elm Grove" imprint, which she created for her memoirs. "We didn't really want to do all that work, but we didn't like how the (original publisher) was trying to control what we were doing," Crocker says. "Obviously, we hired professional editors and professional designers. Most importantly, Steve had a concept and his dream, and it was important to make that happen in the right way."

If you go

Who: Mystic author Ruth W. Crocker

What: discusses and signs "People of Yellowstone," a book of portraits and essays she collaborated on with photographer Steve Horan

When: 2 p.m. Sunday

Where: Bank Square Books, 53 West Main St., Mystic

How much: free, books available for purchase

More information: (860) 536-3795, peopleofyellowstone.com