On Friday, the Roosevelt Middle School seventh-grader saw Ocean Beach for the first time.
Jack ran 3.1 miles through the park with his 700 schoolmates to get there, the first time he had gone that far on foot.
Along John F. Kennedy Memorial Drive, he got his first glimpse of the bison, the Rose Garden and Rainbow Falls.
It was a field trip with a lot of firsts for Jack and many other students from his middle school in the city's Richmond District.
Before the trip, an informal school survey found that about half the students had never been to Ocean Beach or much if any of Golden Gate Park, Principal Michael Reimer said.
Few had ever run 3 miles.
"You realize the kids don't get out too much," Reimer said. "They don't have a whole lot of experiences we take for granted."
The school-wide trip was a daylong combination of sightseeing, physical education and science, school officials said.
After the run, students, in groups, headed to the beach or areas of the park to pick up trash, the hands-on part of an environmental education unit in science class.
"We get to run, be with friends, see a lot of Golden Gate Park, and we help the environment," said seventh-grader Angus Li, 13. "And we're having fun while we're doing it."
The bonus? "No class," Angus said with a smile.
Teachers and parents organized the field trip, covering the $4,000 to $5,000 cost with the help of community donations.
Reimer said he was skeptical that such a large-scale school trip could work. He lost sleep worrying how he, parents and staff would keep tabs on 700 adolescent kids running 3.1 miles through Golden Gate Park.
With the sun shining over Ocean Beach late Friday morning, hundreds of sweaty, smiling kids streamed through the finish line at the park's soccer field.
It was the first of what Reimer hoped would be the annual Roosevelt's Restoration Run.
"It's one of the most ambitious goals I've ever seen out of a school," Reimer said. "I'm really proud."