I'll second the thought that Powderhorn is a great little ski area. It's very friendly, often gets excellent snow (it's well named!), and has some very good terrain as well. It's probably 45 minutes from downtown GJ.
Grand Junction is in the far western part of Colorado, not far from Utah. There are no major ski resorts in the immediate vicinity, but Aspen, Telluride, Beaver Creek and Crested Butte are all within 150 miles, and Vail is just over 150 miles. If you have to go through Montrose and Gunnison to get to Crested Butte, it's more like 170 miles.