We say goodbye to Aubrey Kerr McClendon, the co-founder, former chairman and now former chief executive of Chesapeake Energy Corp., who steps down and out effective April 1 after 24 years. Admit it, it’s the sad end to an exciting era. An entrepreneur and a maverick, he built the company from a $50,000 investment to become the nation’s most active driller and No. 2 gas producer. He did it by taking risks with new technology, new plays and new financial structures.

Credit McClendon this:

  • He fearlessly led the charge into the unknown territory of shale plays;
  • He changed the way producers fund resource-play development with creative joint-venture financings;
  • He directly and indirectly wooed numerous international companies and billions of dollars of investments into the U.S.;
  • He discovered the Haynesville shale, one of the world’s largest gas fields, as well as the Utica, Tonkawa, Mississippi Lime, and Powder River Niobrara;
  • He changed the paradigm for how the U.S. approaches its energy needs by opening up hundreds of years of new gas reserves.

George Mitchell may have cracked the code for economically drilling shale-trapped hydrocarbons, but McClendon amassed an army of rigs and went and did it. Today, Chesapeake holds some 15 million acres in 10 of the top U.S. shale plays, with 20 trillion cubic feet equivalent of proved reserves. Not bad for a kid starting an oil and gas company soon out of college.

His love of land reflects his start as a land-man. Regardless of the cost, land prospective for shale was cheap, he believes.

“The difference between paying $1,000 and $15,000 per acre is frankly just not that big of a deal, because gas reserves are so high per well in these shale plays,” he told me after Chesapeake’s third shale joint venture. “You’re talking about finding costs measured in 10 or 25 cents per Mcf—gas prices can move that much in a day.”

When questioned about concerns of knowledge transfer following his deal with China national oil company CNOOC in the Eagle Ford, he said, “At the end of the day, it’s not the technology that is proprietary; it’s the acreage. I can teach you how to find oil in the Eagle Ford, but if you don’t have any acreage, you can’t do it.”

Chesapeake gobbled up acreage in emerging resource plays; too much, some would say. McClendon may have only himself to blame for the gas glut. You could argue that he is largely responsible for the frenzied resource play land grab that forced hold-by-production drilling deadlines, and was the instigator of the many joint ventures with drilling-carry obligations. When the gas markets inevitably became saturated, Chesapeake and others found the horses galloping at full stampede and no way to stop drilling.

McClendon recognized the gas worm had turned and in 2010 announced Chesapeake would become a leading oil producer, though it produced virtually none at that time. Today, the company is in that transition, producing 150,000 barrels of oil and liquids a year. But his time is up, the mob has stormed the castle.

Those who had once bought into Chesapeake exactly for McClendon’s advance-charging spirit got nervous when he kept charging in the face of plummeting gas prices. Revenues retreated, and debt piled on to feed the massive drilling effort. In an effort led by corporate takeover marauder Carl Icahn, McClendon was targeted for takeout for the good of the shareholders.

His final undoing came as a result of perceived improprieties, including borrowings to fund his personal interests in Chesapeake’s Founder Well Participation Program, the revelation of a secret $200-million hedge fund co-owned with SandRidge chief executive and Chesapeake co-founder Tom Ward, and using company cash for personal perks. An internal Chesapeake investigation has since cleared him of wrongdoing, but the SEC continues to probe.

Are shareholders better off without Aubrey McClendon at the helm? The 7% share-price upswing immediately following the announcement would suggest they think they are. I don’t doubt Chesapeake will do fine, slimming down its portfolio and slowing to harvest the sweet spot of what Mc-Clendon has amassed. But it won’t be revolutionary any longer.

And with something like $38 million due to him, it’s not like McClendon, 53, has to find a job right away. But he just might be motivated to go out on his own terms and on top. If Halcon Resource’s Floyd Wilson can build a $4.5-billion company on reputation in a year’s time, Aubrey can too. Don’t be surprised to see McClendon charging his way through land grabs once again.