Jessica Simpson is sure determined to prove she's a real country girl -- and now she's got the cold beer to go with it!

In her new ad for Stampede Light Plus, the Texas-born Simpson is in full cowgirl uniform, complete with cowgirl hat and bales of hay, looking quite ready for a roll in it. Jessica says in the copy that she "likes a cold beer once in a while," and ever the entrepreneur, she holds 15% share in the brand. Yee haw!