The resort's Peak 6 project would add nearly 550 acres of skiable terrain, two lifts, a restroom facility and warming hut.
Some opponents say cutting trees to make more ski runs could hurt Canada lynx, while some residents have objected because they fear overcrowding in town.
The plan has the support of 45 individuals and environmental groups.
Vail Resorts Inc., which operates the resort, says it expects to have the new terrain ready for the 2013-2014 ski season.
(Copyright 2012 The Associated Press. All rights reserved.)