But fourth place was something of a triumph for top-placed New Zealander Janina Kuzma (27), of Wanaka, who is still recovering from a broken back.
The Cardrona event was the first opportunity for the world's best freestyle skiers to begin gathering points towards qualification for the 2014 Winter Olympics in Sochi, Russia.
Sixty-three skiers took part in perfect weather.
Yater-Wallace grabbed the lead with a "huge" second run consisting of a double cork 1260 mute grab, an alley oop flat spin 540, a 900 tail grab, a 1080 tail grab and a switch right side 900 mute grab.
The women's event was won by Devin Logan (19), from West Dover, Vermont, with 83 points, despite not landing her first run.
Last year, Logan was the top female freeskier in the world, winning the Association of Freeskiing Professionals' overall championship title for the second year running.
Kuzma, of Wanaka, who finished fourth on 76.6 points, said afterwards she considered herself lucky to be one of the 12 finalists at the end of the qualifying round.
An Australian raised in Indonesia who is now a New Zealand citizen, Kuzma damaged her back at Copper Mountain, Colorado, while working on a new trick last December.
"I just kind of landed on top of the pipe, fell backwards from the top into the middle, so fell [7m] on my back and broke one of the wings on my spine."
Despite the pain, she continued skiing through the rest of the season "with a really sore back" that spasmed "all the time".
When she returned to New Zealand she had her spine X-rayed.
"I got a phone call saying we've got some good news and some bad news. You broke your back but it looks like it's healed."
She now wears a back brace while competing and she has repeated the trick that caused her crash, although it was not in her routine yesterday.
Kuzma has more events to compete in here before returning to the United States for her 23rd consecutive winter.
The snowboard World Cup halfpipe semifinals and finals are on Sunday.
