Families started streaming into the South Dakota School of Mines & Technology's Museum of Geology the minute the doors opened at 3 p.m. Saturday, but it wasn't just to see the fossils.

They passed through spider-webbed gates and climbed stairs lined with jack-o-lanterns to reach the museum, flooded with fog.

The museum hosted its second annual "Night at the Museum" event, part Halloween party, part educational day out, organized by the school's Paleontology Club.

Fun and educational activities supplemented the usual exhibits. Costumed student volunteers from the School of Mines guided costumed children through the activity booths.

Activities included a dig box where kids could uncover fossils, a booth where children could paint plaster casts of fossils, an exhibit showing the differences in teeth among carnivores, herbivores and omnivores, and a fluorescent mineral room.

Mat and Natalie Bergendahl of Rapid City had a great time.

"We enjoyed looking at all the different rocks," Mat Bergendahl said.

Their 5-year-old son, Ethan, knew exactly what his favorite part was.

"Looking at the rocks that glow in the dark," he said, "and the candy."

Annie Woodle, also from Rapid City, brought her two boys, Aiden and Teagon.

Aiden's favorite part was the candy, and Teagon's favorite was the T. rex.

Teagon said, "When I grow up, I want to be a paleontologist."

More than 500 people attended the event in its first year in 2007, and more were expected by the end of the day Saturday.

"Everyone pitched in and helped out," said Heidi Minkler, program assistant at the museum. "It was much easier than last year."

Danielle Olinger, president of the Paleontology Club at the School of Mines, said, "It's a way for us to get the community into the museum to learn about geology and so they don't forget about us."

Laura Gierach, a student employee at the museum, said she hopes the event will become an annual affair.