The county's commissioners say that adding large industry, such as oil and gas, would put a strain on natural resources.
Oil and Gas
State regulators deny accusations that the fines are part of an effort to put small drillers out of business.
The USGS said the Mancos Shale formation holds about 66.3 trillion cubic feet of gas, up from 1.6 trillion estimated in 2003.
Around the country, and in Colorado, houses, schools and shopping centers are being built on old oil and gas fields.
As lawmakers start the 2016 session, Colorado's governor lays out his biggest priorities, and faces questions about promises made last year.