Collison, who won Pacific League championships in both events on May 4, needed to finish among the top three in her heat or pick up one of the next three fastest marks across both heats to move into the 1,600 championship event.
She accomplished that after making a strong push in the last 50 meters or so.
"I just wanted to hang in there and just be way more aggressive," said Collison, who made her first appearance in the State Meet after notching a personal-best mark of 4:54.84 at the CIF Southern Section Masters Meet at Norwalk-based Cerritos College on May 25. "It's sort of an intimidating place because everybody here is good.
"I have to stay more aggressive [today] because there's no excuse not going my fastest."
Crescenta Valley Coach Mark Evans said he wasn't sure if Collison, who ran in the first heat, qualified at first.
He looked at the results sheet to be positive.
"She had a great push toward the end," Evans said. "In the first 1,000, she ran very well and was right with the top three or four runners.
"Then a group gapped her a little bit, but she never gave up. Other than that, she ran a great race and got what she needed to advance."
Loyola High junior distance runner James Kostelnik will participate in the boys' 3,200 race at 8 p.m. today.
Kostelnik, a Glendale resident, will make his first appearance at the State Meet after he clocked a personal-best time of 9:11.24 at the CIF Masters Meet.
He has the ninth-best time among the 31 competitors attempting to win the state championship.
Kostelnik won Mission League championships in the 1,600 and 3,200 races last month at Sherman Oaks Notre Dame High.
CHARLES RICH covers sports. He can be reached at (818) 637-3228 or by e-mail at firstname.lastname@example.org.