Spruce Beetle Outbreak (IMAGE) University of Colorado at Boulder Caption A new CU-Boulder study indicates the current spruce beetle epidemic in Colorado, including on Wolf Creek Pass shown here, is caused primarily by drought. Credit University of Colorado Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.