Petulant and street savvy, they were children nonetheless. One girl said she used a butter knife and a library card to break into vacant houses. But after she began living in one of them, she ate dry cereal for dinner for weeks because she did not realize that she could use the microwave to boil water for Ramen noodles. Another girl was childlike enough to suck her thumb, but dangerous enough to carry a switchblade.

They camped in restricted areas, occasionally shoplifted and regularly smoked marijuana. But they stayed away from harder drugs or drug dealing, and the older teenagers fiercely protected the younger runaways from sexual or other physical threats.

In waking hours, members of the group split their time among a park, a pool hall and a video-game arcade, sharing cigarettes. When in need, they sometimes barter: a sleeveless jacket for a blanket, peanut butter for extra lighter fluid to start campfires on soggy nights.

Betty Snyder, the newcomer in the park, said she had bitten her mother in a recent fight. She said she often refused to do household chores, which prompted heated arguments.

“I’m just tired of it all, and I don’t want to be in my house anymore,” she said, explaining why she had run away. “One month there is money, and the next month there is none. One day, she is taking it out on me and hitting me, and the next day she is ignoring me. It’s more stable out here.”

Members of the group said they sometimes made money by picking parking meters or sitting in front of parking lots, pretending to be the attendant after the real one leaves. When things get really desperate, they said, they climb into public fountains to fish out coins late at night. On cold nights, they hide in public libraries or schools after closing time to sleep.

Image Betty Snyder, 14, right, with her friend, Christian Height, 14, at Hawthorne Park, a gathering place for local runaways, in Medford, Ore. Christian is not a runaway. Credit... Monica Almeida/The New York Times

Many of the runaways said they had fled family conflicts or the strain of their parents’ alcohol or drug abuse. Others said they left simply because they did not want to go to school or live by their parents’ rules.