Having written seven books that deal with the Minnesota wilderness, Cary J. Griffith says a simple message runs through all of them: "It can be dangerous out there."

The Rosemount man's "Gunflint Falling," in stores Tuesday, features plenty of danger. Griffith's fourth work of nonfiction (he also has three novels, with another, "Dead Catch," coming this June) is about the 1999 blowdown in the Boundary Waters Canoe Area Wilderness. Some estimate that it leveled more than 48 million trees and Bruce Kerfoot, who owned the Gunflint Lodge, told Griffith the winds moved 4 to 8 feet of water from the west end of Gunflint Lake to the east.

It was Independence Day weekend, so lots of people were there. And Griffith tells many of their stories, especially of people who were caught in the middle of it — including professor and seasoned camper Vicky Brockman, whose pelvis was fractured in numerous places when a tree fell on her, and Lisa Naas, who was on her second trip to the Boundary Waters. She was concussed and nearly died after a tree landed on her.

Griffith began to hear these stories when he interviewed more than 100 people for "Gunflint Burning," his 2019 book about the Ham Lake fire of 2007, one of the largest blazes in Minnesota history.

"Almost everybody told me that the Ham Lake fire burned so intensely because of the blowdown and many of them had really dramatic stories about the blowdown," said Griffith, who visits northern Minnesota at least once a year. "Eventually, when I was doing research, I came across Vicky and Lisa, who I found and spoke with. Both of them were really interesting, but so were the rangers I interviewed. The more I got into it, the more drama I heard."

Much of that drama boils down to something Griffith often returns to in his writing: What do resourceful people do when 911 isn't available to help them out of a jam? Having been on what was supposed to be a 2½-hour North Shore hike in the late 1990s with his sons and a buddy that turned into a seven-hour ordeal when they got lost, Griffith has some experience with that.

Author Cary J. Griffith

"Gunflint Falling" is a wide-ranging book, shifting between multiple adventurers who were in the BWCA when the blowdown hit, as well as wilderness officials and others who strategized how to inform the public about what was going on and rescue those who were trapped. Griffith's website, carygriffith.com, has additional materials and photos that couldn't be included in the book.

Some stories that are included: An entire family takes refuge when it looks like their house is about to collapse around them. U.S. Forest Service pilot Pat Loe manages to land his plane amid downed trees so rescuers can then figure out how to carry Brockman, in intense pain, over piles of lumber, to the plane and eventual safety. It's a cautionary tale but, even more, Griffith thinks it's about how awe-inspiring nature is.

"When people step off the grid and go in the wilderness, they sometimes don't have an informed appreciation for what can happen to you, whether it's somebody getting killed by a grizzly or whatever," said Griffith. "What 'Gunflint Falling,' like 'Gunflint Burning,' tells is the story of how dicey it can be. But we're all drawn to it. I mean, you have to be careful, but how could anybody plan for a derecho, especially happening at that latitude? The people in the book were all pretty savvy. Nobody made dumb mistakes."

The message is the same one Griffith gave his kids: "Be careful out there." But the author — whose next nonfiction book may be "Gunflint Rising," about efforts to rebuild the Ham Lake area — prefers to focus on stories that have happy endings. He wants to emphasize the benefits of the wilderness, even as he captures its dangers.

"When I spend time outside — and I do a lot of hiking and biking and stuff — it gives me a sense of grace, a feeling I can't get in any other way," said Griffith. "I'm kind of agnostic, I guess you'd say, but for me the wilderness is my spirituality. The Boundary Waters I consider to be a spiritual landscape and when I enter the Boundary Waters or wilderness like the Boundary Waters, it gives me a sense of the divine."

Griffith talks about "getting quiet" enough to discover what wild places have to offer us. But also about remembering that they are wild.

"We're all familiar with windstorms. My house backs up to a 47-acre wood and I'm back there almost every day and after it really blows hard, you usually see a tree or two down in those woods," said Griffith. "But nothing quite like what happened to the people in the Boundary Waters on that July 4th."

Gunflint Falling: Blowdown in the Boundary Waters

By: Cary J. Griffith.

Publisher: University of Minnesota Press, 280 pages, $25.95.

Events: Book Launch, 7 p.m. Tues., Magers & Quinn, 3038 Hennepin Av. S., Mpls. Free, but registration required at magersandquinn.com. In conversation with Chris Knopf, executive director of Friends of the Boundary Waters, 6 p.m. Feb. 8 at Next Chapter, 38 S. Snelling Av., St. Paul. Free.