At times Saturday, the long lines to see famous authors rivaled those to get a soft taco or a pulled pork sandwich at the sixth annual Tucson Festival of Books on the University of Arizona Mall.

What started as a fair for bibliophiles has turned into a weekend of free, family-friendly entertainment that, in the past, has attracted 100,000 people over two days.

“We believe it is our largest single-day crowd that we’ve had and it was totally, totally full” Saturday, said Marcy Euler, executive director of the Tucson Festival of Books, which continues today.

She didn’t have a specific crowd estimate yet but said “a combination of things” contributed to the turnout. “The weather was tremendous. The lineup of authors we had was phenomenal. I think that we had a lot of things happening with social media that were driving interest well in advance of the festival — lots of tweeting and Facebooking by authors, by fans, by exhibitors, by sponsors. I think all of those things in combination worked to drive traffic to us,” Euler said.

Advanced promotion was so successful that fans began lining up an hour or more before some authors spoke and venues quickly filled.

Barbara Schmidt has attended the festival several times, but it was a first for her friend, Jan Knaus. The women arrived at 9:30 a.m. and were heading home, free book bags in hand, at around 4.

“I come here because it’s exciting and they keep adding more. We went to two lectures. It’s so hard to hear all the lectures, there are so many good ones,” Schmidt said. “But they can never seem to get enough food tents. There are always lines.”

Despite a wait to eat, Knaus is already planning to attend the book festival next year.

“I’m excited. I see why it needs to be a two-day thing,” Knaus said. “I think it needs to be three days.”

Euler said she has heard that suggestion a lot, but it isn’t practical. At least not yet.

“We want to be the best two-day festival that we can be,” she said. And, “we are really maxed out on volunteers for two days. Because it’s all volunteer-run, adding a third day is a burden, particularly on a workday. At least in the short term it’s not something we’re considering.”

Julie Gates came to the festival with her mother, Barb Mahaffa, who is visiting from Iowa.

“She’s a teacher and I was a teacher,” Mahaffa said.

“And we love to read,” Gates added.

“I think it’s wonderful so many people are reading,” Mahaffa said.

The only downside, Gates said, is the long lines for some of the author presentations.

“You have to design your day around it,” she said.

Long lines mean festival organizers are doing things right, Euler said.

“From our perspective that tells us we are drawing the kinds of authors people want to see. And instead of having the opposite problem where we can’t fill our venues, we have people who are clamoring,” she said.

“I know it’s unfortunate for the people who cannot get in, but I think that is also indicative of the quality of the authors that we get, both local and national. They have great audience appeal.”

The festival’s appeal isn’t just to those wanting to hear favorite writers speak.

Danielle Garraigan and her four children — ranging in age from 5 to 16 — arrived at the festival late Saturday afternoon.

“Mainly we’re going to hit the kids stuff,” she said. Last year “they gave out free books and crafts and had puppets to make in the kids’ area.”

Curious George was greeting children on Saturday along with Clifford the Big Red Dog and at least one of the beasts from “Where the Wild Things Are.”

Habitat for Humanity put children to work painting birdhouses and in Science City kids got to take turns sitting on a mini hovercraft.

Ken and Ginger Lynch, along with friends visiting from Prescott, browsed through dozens of booths run by exhibitors and booksellers before finding Science City.

“This is the whole section I’m interested in. I wish we had started here,” Ginger Lynch said.

Science City, which features all manner of hands-on experiments, demonstrations and lectures on astronomy, agriculture, computers, physics and nature, was a favorite of Rosa Rubio and her family, too.

Rubio, of Catalina, was at the festival with her 9-year-old son, Gabriel, and her fiancé, Omar Rodriguez. They learned about the festival when Gabriel brought home a flier from school.

“It was all very informative. I like how they break it all down,” Rodriguez said. “We’ll definitely come back again. This really opened our minds to all the great things there are to do in Tucson.”

Gabriel was impressed by the sunspots he saw through a telescope.

“It was cool that you could see the sun,” he said.

La Shondra Jones, a four-time book festival attendee, was attending lectures by writers who specialized in romance, such as Daniel Jones, editor of the New York Times’ Modern Love column.

“The festival is great for the community. It gets everybody out here and it seems to be getting bigger every year,” she said. “There’s something for everybody, not just books but food, other cultural stuff — and it’s free.”

In contrast to Jones, it was the first time at the festival for Elias Santos, who was interested in science fiction and fantasy. He was excited to see children’s author R.L. Stine was at the show.

“The ‘Goosebumps’ books really hooked me on reading,” she said.

“What’s most impressive is the number of people out here,” she added. “It’s pretty spread out but you see it when you try and get some food.”

Two dozen vendors are selling food and beverages at the festival, with options ranging from typical fair food — shaved ice, soft tacos, kettle corn — to dishes served up from local eateries such as Pastiche, Beyond Bread and Tucson Tamale Co.

At its peak Saturday, food-booth lines ran 50 customers deep.

Aromas wafting from the food booths got the attention of Ed Komenda, who was visiting from Las Vegas.

“I love it! Between the smell of books and smoking pork, it’s like heaven,” he said.

Komenda, a writer at the Las Vegas Sun, drove down to Tucson with a colleague just for the festival. It was his first time visiting the state. As it turned out, his friend Richard Lange, author of “Angel Baby” and “This Wicked World,” was speaking on a panel.

“It was a chance to see the festival, see my friend and see Arizona,” Komenda said.

The Star’s Tom Beal, Luis Carrasco and Jill Jorden Spitz contributed to this article.

Contact reporter Kim Matas at kmatas@azstarnet.com or at 573-4191.