Industrialist, political kingmaker and part-time Colorado resident David Koch, whose death was announced Friday, leaves a large behind-the-scenes political legacy in Colorado.

One the state’s top advocacy organizations, Americans for Prosperity, was the work of David Koch and his brother Charles.

Americans for Prosperity’s Colorado office declined to comment Friday on David Koch’s passing and referred Colorado Politics to Koch Industries, which released a statement from his brother.

“Twenty-seven years ago, David was diagnosed with advanced prostate cancer and given a grim prognosis of a few years to live,” Charles Koch stated. “David liked to say that a combination of brilliant doctors, state-of-the-art medications and his own stubbornness kept the cancer at bay. We can all be grateful that it did, because he was able to touch so many more lives as a result.”

David Koch has owned two homes in Aspen for decades, according to the Pitkin County Tax Assessor’s Office.

The Kochs founded AFP in 2004 as part of a network of advocacy organizations and think tanks to promote libertarian values.

“Mr. Koch was a genuinely passionate and generous person who gave so much of his time and money to make a difference in people’s lives,” said Michael Fields, who left AFP’s Colorado leadership last year to lead a new conservative advocacy organization, Colorado Rising Action.

“He will certainly be missed.”

The Kochs have been notably press-shy in the state.

They routinely assembled top thinkers, politicians, media and operatives for donor summits at the The Broadmoor resort in Colorado Springs.

The event in the past has been open only to media who would agree to ground rules on what could be covered. (Colorado Politics has declined to accept those restrictions on ethical grounds.)

Friday morning in Steamboat Springs, another Colorado beneficiary of the Koch network, the Steamboat Institute, hosted hundreds of top conservatives for an annual weekend summit.

The passing of Koch went unmentioned in the opening remarks of the institute’s CEO, Jennifer Schubert-Akin, as an audience of about 400 prepared to hear a morning speech by Interior Secretary David Bernhardt, a Western Slope native.

The organization did not have a statement about Koch’s passing Friday, a spokesman said later.

Other Colorado members in the Kochs’ State Policy Network include the Independence Institute in Denver, the Centennial Institute in Lakewood, the Leadership Program of the Rockies in Colorado Springs and The Mountain States Legal Foundation in Denver.

“David Koch was a great leader in the libertarian/conservative movement,” Jon Caldara, president of the Independence Institute, told Colorado Politics. “His success can be measured by the pure hatred thrown at him by those who work for socialism and government control. What made him unique for his time was his ability to recognize that we can’t move the political needle merely by donating to politicians.

“David Koch invested his time, talent and resource to building an infrastructure for ideological change. He spurred others to be involved. The left will have to find a new boogieman.”

The State Policy Network’s annual meeting will be in Colorado Springs at The Broadmoor Oct. 29 to Nov. 1.

Last year, AFP worked on at least two campaigns against Colorado ballot measures, both of which ultimately failed. Proposition 112 would have increased setbacks for oil and gas from schools, homes and other occupied buildings. AFP also successfully campaigned against Amendment 73 which would have increased income taxes on high earners to benefit education.

The Kochs weren’t as successful backing Colorado candidates last year, however. Walker Stapleton lost the governor’s race. AFP reportedly spent up to $1 million to back the GOP nominee, as environment groups dropped $3.2 million behind Democrat Jared Polis and legislative Democrats.

Despite AFP’s help, incumbent Sen. Tim Neville of Littleton and Christine Jensen of Arvada lost their 2018 Senate races as Democrats seized the majority in the upper chamber and with it full control of the state’s legislative and executive branches of state government.

In June, Americans for Prosperity made two announcements that could have far-reaching impact in Colorado.

One, Americas for Prosperity plans to put resources behind incumbent Republican U.S. Sen. Cory Gardner for re-election next year, but also that the organization said it would consider candidates’ positions and not their party affiliation in the future, meaning Democrats could receive AFP endorsements.

Gardner’s campaign had no response to Koch’s passing Friday.

In June, at the time of its Gardner announcement, AFP told Colorado Politics that David Koch was no longer actively involved with the organization because of his health.

Colorado Politics’ Marianne Goodland contributed to this story from Steamboat Springs.