BLACK SPRINGS, Ark. — Just off Highway 8, amid the cattle pastures, chicken houses and hog farms in these rolling hills, is Pole Vault Lane. Its short, gravelly path is decorated with pennants, and it leads to a metal building about half the length of a football field. It is a hangar of sorts, or, more accurately, an indoor runway designed to produce short but spectacular flight.

On Saturday morning, the identical twins Lexi and Tori Weeks traveled two and a half hours to challenge the national indoor pole-vault record for high school girls: 14 feet 2 ¾ inches. In early January, the twins vaulted 14-0 ½ and now ranked as the country’s top female prep vaulters, an extremely rare achievement for siblings in an event that requires enormous technical precision, along with speed, core strength and spatial awareness.

Inside the Arkansas Vault Club, about 50 spectators gathered for Saturday’s invitational meet. Most were parents of the participants, or grandparents, sisters, brothers, boyfriends, girlfriends. Some huddled near a wood-burning stove against the uninsulated chill. Others brought camping chairs and sat wrapped in blankets or helped themselves to hot chocolate.

“You’ve got to be coming here; you don’t just wander in,” Johnny Benefield, 71, the twins’ maternal grandfather, said of the isolated location.