On day one, both Parks and Cox made it through to the six-woman super final, where Cox finished in second place and Parks in fifth.
In the second event, Parks dominated finishing first in all three rounds of the event to take victory with Cox recording back-to-back second place performances.
Parks and Cox will return to World Cup competition in Calgary, Canada, on January 3, where they will join team-mate Matthew Graham who placed 22nd at the first World Cup event in Ruka, Finland.
A number of NSWIS and junior Australian athletes also competed at the event, with James Matheson, Rohan Chapman-Davies, Roanna Humphries, Madii Himbury and Jakara Anthony all recording top-10 performances which will see them receive a World Cup development start in Deer Valley, UT, USA, in mid-January.
On day one James Matheson and Roanna Humphries both placed sixth in the super final, with Jakara Anthony ninth and Claudia Gueli 13th also making it through to the first round of finals.
On day two a number of athletes also advanced to the final round in finals, with Rohan Chapman-Davies seventh, Jakara Anthony ninth, Madii Himbury tenth, Krystle Yin 14th and James Matheson 16th.
IMAGE: Podium athletes from the day two event at the US Selections © www.urtur.com