If you’re a part of the Krantz family, summer weddings, vacations and babies are not recommended.

“My dad used to say, ‘You have 90 days to make all the money you’re going to make for the year. Now go,’” said Beth Krantz-Davis, who handles marketing for Adventureland Park, Inn and Campground, the resort her father built. Last year, Krantz-Davis delivered her third child in June. Six days later, she was back to work.

The state’s tourism season is a crucial time for this family. The founder of Adventureland, Jack Krantz, passed away in January, but three generations of his family remain involved with its day-to-day operations: his wife, Jan; two daughters, Molly Vincent and Beth Krantz-Davis; his sons, John, Matthew and Michael; a nephew, Doug Cornwell; and two of John’s children, John Jr. and Madeline.

The eldest of seven children, John Krantz, Adventureland’s president, remembers the day his father came home with some drawings and said he wanted to start raising money to build an amusement park.

“Dad said I looked at him like perhaps he was crazy,” he said. “Besides him, none of us had ever been to an amusement park before.”

“Jack liked challenges,” Jan Krantz, Adventureland’s CEO, said of her late husband. “Being a builder, I think he saw the park as a new challenge for him, and something that was desperately needed in Iowa and the Midwest at the time.”

Adventureland’s first full season was in 1974. The park had opened the previous year, but closed for repairs after a tornado damaged some of the buildings. At the time, the amusement park consisted of the small main street area and a few rides, but it has now grown to more than 100 rides, shows and attractions.

The theme park attracts about 550,000 visitors per year, mostly from Iowa, but also drawing from Nebraska and parts of Illinois, according to Molly Vincent, who handles advertising and communications for the park. About 200 full-time staff and 1,000 seasonal workers are employed there. The family has had offers over the years to buy the 164-acre resort. In the early 1980s, out of fear of a hostile takeover, Jack decided to buy out his stockholders to make the park privately held.

“There have been several offers, but they were never entertained because Dad built this park and wanted it to stay in the family,” Vincent said.

John Krantz and cousin Doug Cornwell started working for the family business as teenagers 35 years ago, before the park was open to the public, and they’ve continued working there. Some of the younger Krantz children and other family members worked in the games area when they were as young as 10 or 11. John Jr., a recent graduate from the University of Iowa, is beginning his 11th season at Adventureland.

“It wasn’t that we felt that we had to start working in the business as a kid; it was more like, ‘How long do we have to wait so we can get out there?’” said Krantz-Davis. “We saw our mom and dad go there to work every day, and we wanted to get out here and join them.”

Jack and Jan encouraged their children to further their education after high school. Matthew, who manages the Adventureland Inn, said his father was a strong believer in education and applying it toward doing what you love. Matthew, Michael, Molly and Beth attended the University of Iowa. Matthew and Molly also studied law at Drake University.

“Matt was running the games department while he was finishing up law school,” Jan Krantz said. “I would come into work in the summer and find him asleep at his desk after staying up late to study for the bar exam.”

Molly said she and Matthew found that there were so many real-life applications between their classes and Adventureland that it made sense to apply what they had learned in the family business.

“I started out in college as a science major, but I remember at one point realizing that I didn’t want to spend the rest of my life in a lab,” Matthew said. “This is one of the greatest businesses in the world because everybody who comes here is happy. It’s not like getting your brakes fixed or going to the dentist.”

The Krantz family expects 2006 to be a good year for Adventureland, partly because of the two new rides it added this season: The Frog Hopper for children, and The Splash Over, a water and thrill ride. But Jack Krantz’s absence this year is impossible to ignore, not only for his family, but for the staff who worked alongside him.

“We all loved and respected him so much,” said Doug Cornwell, a nephew and Adventureland’s director of operations. “Every time I try to do something now that he’s not here, I ask myself, ‘What would Jack do?’”

Matthew thinks of all the times his father would come to the hotel and move a piece of furniture slightly and say, “That’s where that belongs.” If asked why he thought it “belonged” in that particular spot, he would reply, “Because I put it there when I designed it.” Now, Matthew finds himself moving a couch or chairs back in place if they have shifted location a little bit, trying to remember exactly where his dad wanted them.

“We’ve all had dreams where we’ve talked to him and asked him how he would handle something,” Matthew said.

Beth remembers that her dad had an incredible amount of technical expertise. If someone told him there were three ways to solve a problem, he would come up with a fourth that was usually cheaper, easier and better.

“He could solve a problem fast, and he was decisive,” she said. “I think we’ll all miss that. I think his memory is so strong here that our kids will feel it when they start working here.”