A Paddles the Beaver sign is the National Park Service’s first line of defense for cherry trees. Ranger John Kirkpatrick came up with the character in 2007. (Matt McClain/The Washington Post)

John Kirkpatrick knew that putting a beaver in charge of protecting Washington’s treasured cherry blossoms was an idea that challenged logic. It was a bit like making Bernie Madoff treasury secretary. But Kirkpatrick, a National Park Service ranger, had a vision, and his vision had buckteeth, a smile and a message.

Kirkpatrick, 50, called his creation Paddles, and together, he and his cartoon beaver work to keep the more than 3,000 cherry trees around the Tidal Basin and Mall that are exploding into bloom this weekend safe from the more than 1 million visitors expected during the two-week National Cherry Blossom Festival.

Paddles made his debut in 2007, but over the past few years, he has taken on an increasingly visible role in the annual festival. His face has appeared on hats and buttons and Facebook (of course), and now there’s a Paddles plush doll. His cheerful, slightly bewildered visage greets visitors on large wooden placards at 20 cherry-blossom-rich locations. Paddles holds a stop sign with a kind request: “Please don’t pick the blossoms or climb the trees.”

The message couldn’t be simpler, but it’s an admonishment that never really took hold until Paddles began delivering it in the tradition of Smokey Bear, Woodsy Owl and other government-sponsored public service characters. And it’s working, says Jaime Boyle, special events coordinator for the Park Service’s National Mall and Memorial Parks unit.

Learn more about the cherry blossoms around the Tidal Basin

“We don’t have hard numbers,” she says, “but we’ve noticed fewer and fewer people climbing the trees and tearing off blossoms since we got Paddles and started to push the stewardship message.”

Kirkpatrick agrees that Paddles has played a significant role. “You used to see thousands of people walking around holding blossoms,” he says. “Now you only see a few.”

Kirkpatrick, a former successful salesman who abandoned the claustrophobia of a cubicle for an office in the great outdoors, understands the importance of a brand. It was not just by chance that he chose to combat cherry blossom carnage with a friendly cartoon. Paddles, he says, is a win-them-over-with-cuteness method for keeping tourists from damaging Washington’s most treasured and valuable lumber. The festival, which boasts blooms from 12 varieties of Japanese flowering cherry trees, is a $150 million tourist bonanza for the city, festival officials have estimated in the past.

That the cartoon Kirkpatrick chose would be a beaver was unavoidable. It’s the only animal he knows how to draw.

“I give my grandpa credit,” says Kirkpatrick, 50. “He taught me to draw this one stupid beaver and nothing else.”

Trees have a fraught relationship with beavers, of course. And cherry trees at the Tidal Basin have not been immune from nighttime nibbles by the semi­aquatic rodents.

#DCBlooms: A daily video portrait of cherry trees around the region

The attacks reached crisis levels in 1999 when a rogue beaver took down several trees around the Tidal Basin during the peak of the festival. It was normal activity for a beaver, but that didn’t make it any easier for park officials to swallow.

“We call him blankety-blank,” Earle Kittleman, a Park Service spokesman, told The Washington Post at the time. “Our people are really upset about the trees.”

Additional beavers were soon identified as co-culprits. Investigators determined that it was a family operation and worked to humanely trap and relocate the mother, father and 1-year-old beaver to an undisclosed habitat. They haven’t been heard from since. But other beavers have been known to chomp at the trees on occasion, and among cherry tree devotees there’s always a gnawing sense that surreptitious strikes are in the offing.

Kirkpatrick, who lives in Frederick and joined the Park Service in 2004, acknowledges that, in some ways, making a beaver the face of cherry-tree protection was counter­intuitive. And not everyone was on board with the idea at first.

“There are some people who don’t get it and say, ‘You can’t have a beaver protect trees!’ Well, yeah, maybe in real life you can’t, but this is a cartoon. He’s not going to tear anything down,” Kirkpatrick says.

He initially imagined Paddles as a well-behaved beaver who would go back and tell his harmful pals to halt their Tidal Basin carpentry. But that narrative, he decided, placed unfair blame on nature’s eager engineers.

As Kirkpatrick points out, the damage the beavers have done to the trees is far less than visitors do each year. During the two-week festival, 1 million or more people will admire the beauty of the cherry blossoms — while leaning and climbing on the trees, packing down the dirt around their roots, and leaving four tons of trash to be hauled away. When it comes to environmental destruction, beavers have nothing on humans.

Animal mascots have a storied history in public awareness and safety campaigns. Smokey Bear has delivered the “Only you can prevent forest fires” message since the 1940s. The slogan changed from “forest fires” to “wildfires” in 2001.

Woodsy Owl, a 1971 U.S. Forest Service creation, taught Generation Xers to “Give a hoot — don’t pollute.” Less successful is Leon the Lightning Lion, a 21st-century mascot created by the National Oceanic and Atmospheric Administration to warn kids about the danger of lightning. “When thunder roars, go indoors” is a fine message, but Leon’s place in the public service mascot pantheon is borderline.

“There have been animal cartoon characters just about from the beginning of advertising,” says Claudia Caplan, a senior vice president at MDC Partners, a New York-based marketing agency. “Part of the reason that you have animals or anthropo­morphic characters like the Aflac duck is that it delivers the message in a more memorable, fun and gentle way.” And, she adds, “The cute and fun factor never wears out.”

The success of Paddles can be attributed to a number of factors, Caplan surmises.

“A sign that says ‘Keep your hands off the trees’ is sort of mean and pejorative and wagging your finger, but my guess is that having this beaver do it is less unpleasant to people and more welcome,” she says. “And it probably attracts the attention of children. A child is not going to look at a written sign. But [Paddles] may activate a child not to pull a flower off the tree or even to say to a parent ‘Mommy or Daddy, you shouldn’t be doing that.’ ”

Indeed, says Kirkpatrick, who is married and has two young children. “Kids make great vigilantes. They love to point out to adults what they’re not allowed to do. The kids are getting the message. They are remembering it.”

But, alas, Paddles can’t provide foolproof protection.

As Kirkpatrick is explaining to a visitor at the Tidal Basin how Paddles the Beaver came to be, a young boy five yards away begins shimmying up the gnarled trunk of a soon-to-bloom cherry tree.

Kirkpatrick sighs. “I should probably yell at him,” he says. Then he smiles.

“But he’s a kid. It’s a tree.”