American Express will team with Colorado and Denver tourism officials on a $2 million campaign to pitch summer travel in the state. The public-private effort marks the first time Colorado has advertised to visitors since voters shot down state tourism board funding in 1993. "We've seen a 15% decline in out-of-state visitors, which is one reason American Express stepped up to do this," said Eugene Dilbeck, president of the Denver Metro Convention & Visitors Bureau. A 24-page publication touting summer in the Rockies will run in Travel & Leisure and Food & Wine magazines. American Express will send the publication to 300,000 cardholders and hold seminars for travel agents in 12 targeted cities.