Kenneth Salazar, a fifth-generation Coloradan with ranching roots, is taking his cowboy hat and bolo tie back to the Rocky Mountain region.

The former junior U.S. senator from Colorado and outgoing head of the U.S. Department of the Interior is joining Wilmer Cutler Pickering Hale and Dorr to open a new office for the firm in Denver.

Salazar told The Am Law Daily in a phone interview Thursday that he had spoken with more than a dozen firms, but in the end it was the roughly 20 to 30 lawyers he met at Wilmer that won him over, among them former co–managing partner William Lee, appellate litigation chair Seth Waxman, and Salazar’s former chief-of-staff Thomas Strickland, who joined the firm back in September 2011.

“Tom and I have known each other for more than 30 years—he was the one who actually got me into politics back in the early eighties,” says Salazar, noting that the two had begun their legal careers at old-line Denver firm Sherman & Howard. “We always said we wanted to practice together again at some point.”

Salazar left Sherman & Howard in 1987 to serve as chief legal counsel to former Colorado Governor Roy Romer, who later nominated him to become executive director of the Colorado Department of Natural Resources. In 1994, Salazar returned for a brief stint in private practice at now defunct Parcel, Mauro, Hultin & Spaanstra, before launching his successful 1998 campaign to become Colorado’s attorney general.

He was reelected in 2002, and two years later Salazar announced he would seek the U.S. Senate seat of retiring Republican Ben Nighthorse Campbell. Salazar narrowly beat Republican challenger Pete Corrs—whose brewing company once bought the rights to John Denver’s Rocky Mountain anthem—marking an unlikely political ascent for a man whose father wanted him to become a priest. (Salazar is one of eight siblings—his elder brother John Salazar is a former Colorado congressman who now serves as commissioner of the state’s Department of Agriculture.)

The Obama administration nominated Salazar in December 2008 to head the Interior Department and he left the Senate early the next year. Salazar’s time as head of the Interior Department would be marked by the massive 2010 oil spill in the Gulf of Mexico that resulted in an overhaul of the federal government’s requirements for offshore oil and gas projects.

Salazar worked closely with former Fried, Frank, Harris, Shriver & Jacobson partner Michael Bromwich, who was nominated by President Barack Obama in June 2010 to lead the administration’s review of oil and gas regulations in the aftermath of the Deepwater Horizon disaster. Salazar later tapped Bromwich to head the Interior’s new Bureau of Safety and Environmental Enforcement as part of a reorganization of the department’s responsibilities.

Bromwich left government service and returned to private practice last year at Goodwin Procter. Now joining him in the ranks of The Am Law 100 is Salazar, who after leaving the Interior Department in March had been without a professional home. He poked fun at his lack of employment during a speech last month to law students at the University of Michigan, his alma mater.

“Here I am, speaking to the University of Michigan law [school] 2013 graduating class, and here I am, a graduate of this great law school, and I am unemployed,” Salazar joked. “Maybe I could learn something from you! Those of you who are still looking, maybe we can band together.”

At Wilmer, Salazar’s duties will entail providing public policy and government relations counsel to firm clients, advising on energy matters, and working on environmental and natural resource issues, particularly those that involve Native American lands and interests.

Wilmer co–managing partner Robert Novick, who is based in Washington, D.C., tells The Am Law Daily that his firm is making a strategic decision to enter the Rocky Mountain region, where the federal government owns most of the available land.

“It’s the perfect intersection of law, business, and policy where [Wilmer] really excels,” says Novick, noting that the firm doesn’t take lightly the cost of opening in a new city. “We always look to build off our strengths, and this firm has a long tradition of lawyers doing public service, so it was important for us to bring in a leading lawyer like Ken.”

As an example of Wilmer’s success in expanding to new regions, Novick notes the firm’s opening of an office in Palo Alto back in 2005, which he says has since grown to more than 80 lawyers, making it the eighth-largest firm in Silicon Valley. Novick hopes Wilmer’s new Denver office will also prosper, adding that the firm hopes to capitalize on Colorado’s vibrant natural resource and technology sectors.

Wilmer’s IP litigation and transactional practices frequently work with emerging companies, and Novick believes both will benefit from the firm’s entry into the Colorado legal market. “Boulder has one of the highest number of patent applications in the country,” says Novick, citing a recent report by The Brookings Institution.

Denver has been a popular destination over the past year for Am Law 100 and 200 firms. In December, Stinson Morrison Hecker opened an office in the city by luring a nine-lawyer team from local firm Jones & Keller, according to our previous reports. Last summer Kansas City, Missouri–based Spencer Fane Britt & Browne picked up 22-lawyer Denver firm Grimshaw & Harring, a move that followed Bryan Cave’s merger with Holme Roberts & Owen, Polsinelli picking up 13-lawyer local shop Hensley Kim, Husch Blackwell absorbing 24 lawyers from Jacobs Chase, and Lathrop & Gage merging with Kamlet Reichert.

While Novick wouldn’t say what size he has in mind for the firm’s new Denver office—“We don’t think in terms of size, we look for a strategic fit”—he did say that the firm does hope to supplement Salazar’s presence in the Mile High City. Strickland, who helped lure Salazar to the firm, will remain in Wilmer’s D.C. office.

Wilmer, which earlier this week sold off its Boston-based wealth management arm Silver Bridge Advisors, has been enjoying solid financial growth. The firm saw gross revenue rise 8.2 percent in 2012 to $1.076 billion, while profits per partner rose 6.2 percent to $1.46 million, according to The American Lawyer’s annual Am Law 100 financial data.

As for Salazar, who in March saw the Senate approve the nomination of his successor at the Interior Department in businesswoman Sally Jewell, he remains optimistic about the future of the U.S.’s growing status as a global energy giant.

“The challenge is to get us to a greater level of energy independence,” says Salazar, adding that his experience working on the Energy Policy Act of 2005 and Energy Independence and Security Act of 2007 can be a key resource to potential clients, such as companies seeking to navigate new rules being proposed by the Obama administration governing the oil and gas hydraulic fracturing process on U.S. land.

One company Salazar won’t be representing is BP, which retained Wilmer in 2010 following the explosion aboard an offshore oil rig leased by the London-based company in the Gulf of Mexico that led to the disastrous Macondo spill. “I’ll be completely segregated [from BP],” Salazar says.

The firm’s ongoing work representing the British oil giant was one engagement that helped Wilmer surpass the $1 billion gross revenue mark for the first time ever in 2012.

Other Am Law 100 firms on the move this week include Faegre Baker Daniels, which on July 1 will open its first office following the 2011 merger that created the firm by relocating IP partners Calvin Litsey and David Gross to Palo Alto from Minneapolis and bringing on former congresswoman Mary Bono. Cozen O’Connor also became the latest Am Law 100 firm to head to Minneapolis by hiring eight partners from Hinshaw & Culbertson, according to sibling publication The Legal Intelligencer.

And Hogan Lovells announced a trio of lateral hires from Chadbourne & Parke in international arbitration cohead Oliver Armas and products liability Phoebe Wilkinson in New York, along with litigation and arbitration partner Luis Enrique Graham in Mexico City, according to sibling publication the New York Law Journal.

For the time being Graham will split his time between New York and working remotely from Mexico City, where Hogan Lovells has in the past expressed an interest in opening an office as a gateway to the Latin American legal market, according to U.K. publication Legal Week.