During the summer months there's a nice Farmers' Market in Vail every Sunday. It's situated on the north side of Gore Creek, on Meadow Drive, in close proximity to the town's large parking structure. It compliments the nearby Minturn Market which is held on Saturday and many of the vendors from that smaller but more compact Minturn Market also show up at Vail.
The Vail market is, at least to my impression, significantly larger than the Minturn Market, although not its not as compact and fun to navigate. It features seasonal produce which mostly is grown in eastern and western Colorado. Not too much food is grown at the high elevation of Vail which sits at around 8200 ft (2500 m) above sea level. Besides produce, these mountain markets feature a large selection of locally prepared foods (jams, honey, coffee), a large assortment of food tents serving warm meals, snacks and beverages, and an extensive variety of handicrafts. You can find everything from jewelry, clothes, photographs and paintings, to wine barrel art.
The market is very popular and busy. If you tire of the crowds. it's significantly less crowded a few blocks away on the north side of Gore Creek, where you'll find quieter streets and cafes if that's what you prefer.
Here's some of what you'll see when you stroll through the Vail market: