Qualifying in third the day before, Smith won her quarter-final and semi-final in America and was then not to be denied by Ophelie David, Anna Holmlund or Kelsey Serwa in the final.
Smith brushed all three to one side to make it two from two this season having won the opening round ahead of France's former world champion David in Nakiska in Canada earlier this month.
David again had to make do with second while Sweden's Holmlund edged out Serwa of Canada for third while Brits Emily Sarsfield and Pamela Thorburn did not even make it to the knockout stages.
With the top three the same in both races this season, Smith leads the ladies' ski cross World Cup standings with 200 points, 40 ahead of David who is in turn 40 ahead of Holmlund.
However the men's race did provide a different winner from the opening round as Slovenia's Filip Flisar edged out Brady Leman, Armin Niederer and Jean Frederic Chapuis for victory.
Switzerland's Niederer, who won the opening round in Nakiska, had to make do with third behind Brady but does lead the overall ski-cross World Cup standings with 160 points.
Teammate Alex Fiva, second in the opening round but sixth this time around, lies joint second with Leman on 120 with Flisar going straight in at fourth with 100 courtesy of his win.