Boulder Mountain in Utah, United States makes up half of the Aquarius Plateau of South Central Utah in Wayne and Garfield counties. The mountain rises to the west of Capitol Reef National Park and consists of steep slopes and cliffs with over 50,000 acres of rolling forest and meadowlands on the top. The mountain has a nearly flat summit of ro…Boulder Mountain in Utah, United States makes up half of the Aquarius Plateau of South Central Utah in Wayne and Garfield counties. The mountain rises to the west of Capitol Reef National Park and consists of steep slopes and cliffs with over 50,000 acres of rolling forest and meadowlands on the top. The mountain has a nearly flat summit of roughly 70 square miles. The mountain is the highest timbered plateau in North America and is part of the Dixie National Forest.