This article explains how Britney knew Bryce Dickey:
Rodeo Friend Arrested in Murder of Teen Cowgirl Britney Ujlaky
"An 18-year-old man was arrested Thursday in connection to the murder of
Britney Ujlaky, a 16-year-old girl in rural Nevada who vanished after getting a ride from the suspect, who was one of her friends from the rodeo.
Bryce Dickey, of Spring Creek, was cuffed on one count of open murder. He was scheduled to appear before a judge on Friday afternoon. . ."
The article also explains that Britney thought of him as a "big brother." The article also states that the story of Britney getting a ride from someone in a green ford pickup was made up by Dickey.