A regulatory agency (also regulatory authority, regulatory body or regulator) is a public authority or government agency responsible for exercising autonomous authority over some area of human activity in a regulatory or supervisory capacity. An independent regulatory agency is a regulatory agency that is independent from other branches or arms of the government.

Regulatory agencies deal in the area of administrative law—regulation or rulemaking (codifying and enforcing rules and regulations and imposing supervision or oversight for the benefit of the public at large). The existence of independent regulatory agencies is justified by the complexity of certain regulatory and supervisory tasks that require expertise, the need for rapid implementation of public authority in certain sectors, and the drawbacks of political interference. Some independent regulatory agencies perform investigations or audits, and some are authorized to fine the relevant parties and order certain measures.

Regulatory agencies are usually a part of the executive branch of the government, or they have statutory authority to perform their functions with oversight from the legislative branch. Their actions are generally open to legal review. Regulatory authorities are commonly set up to enforce standards and safety, or to oversee use of public goods and regulate commerce. Examples of regulatory agencies are the Interstate Commerce Commission and U.S. Food and Drug Administration in the United States, Ofcom in the United Kingdom, and the TRAI in India.

Yucca Mountain is a mountain in Nevada, near its border with California, approximately 100 miles (160 km) northwest of Las Vegas. Located in the Great Basin, Yucca Mountain is east of Amargosa Desert, south of the Nevada Test and Training Range and in the Nevada Test Site. It was the site for the Yucca Mountain nuclear waste repository before that plan was scrapped in 2010.

The formation that makes up Yucca Mountain was created by several large eruptions from a caldera volcano and is composed of alternating layers of ignimbrite (welded tuff), non-welded tuff, and semi-welded tuff. The volcanic units have been tilted along fault lines, thus forming the current ridge line called Yucca Mountain. In addition to these faults, Yucca Mountain is criss-crossed by fractures, many of which formed when the volcanic units cooled.

A series of large explosive volcanic eruptions occurred to the north of Yucca Mountain millions of years ago, producing dense clouds of volcanic ash and rock fragments which melted or compressed together to create layers of rock called tuff, forming the mountains and hills of the region. The volcanic eruptions that produced Yucca Mountain ended about 12 million years ago. This explosive volcanism produced almost all (more than 99 percent) of the volcanic material in the Yucca Mountain region.