In 2000, the party gathered nomination signatures to place Ralph Nader on the Oklahoma Presidential ballot but was unable to collect a sufficient amount.

[citation needed] In 2002, the local chapters joined together in issuing a call for the Founding convention of the Green Party of Oklahoma, which was held at the Cleveland County Fairgrounds in Norman on November 16, 2002.

(shortly after this convention Danelle resigned as Secretary and Belinda Silverstar was selected by the executive committee to serve in her place).

The party also elected Alpers, Branum, Silverstar, and Curtis Andrew Beckwith to represent the state at the GPUS national convention in the summer of 2004).

[9] Following this, the party joined with other members of the OBAR coalition in calling for Oklahoma voters to cast a blank ballot for President as part of a so-called "None of the Above" Presidential campaign.

The convention was notable for its adoption of the so-called "Radical Proposal", a bylaws revision that abolished the current state Executive Committee and replaced it with a state Cooperative Council, composed of voting representatives from each of the local chapters, as well as non-voting membership by GPOK members who wish to participate.

[19] In 2007, the party held its Sixth annual convention in Stroud, Oklahoma at the historic Rock Cafe on old Route 66.

The speaker at this convention was Sean Hough, a worker from the Libertarian Party who had come to work with Oklahomans for Ballot Access Reform.

[citation needed] The Ninth Annual Convention was held in Norman in 2010, where the party endorsed Edward A. Shadid in his unsuccessful race for the Oklahoma State House.

[citation needed] In 2016, the Green Party of Oklahoma controversially[27] endorsed Senator Bernie Sanders for the Democratic nominee for President of the United States[3][2] but did not endorse any candidate on the Oklahoma general election ballot for President since GPUS nominee Jill Stein was not on the ballot due to Oklahoma's restrictive ballot access laws[28] (as well as the failure of litigation brought by Presidential nominee Stein.