Soil map (IMAGE) University of Texas at Austin Caption Geomorphic units in Nevada's Boulder City Conservation Easement. The research found that larger creosote plants grow in younger units. Credit Gearon et al. / The University of Texas at Austin Usage Restrictions Include photo credit 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.