The paper petitions weighing 3,000-pounds will be delivered by truck this afternoon to the state Government Accountability Board's office two blocks from the Capitol in Madison.
Recall organizers need to submit valid 540,208 signatures to schedule a recall election against Walker and Lt. Gov. Rebecca Kleefisch.
Four GOP senators are also targeted for recall: Scott Fitzgerald of Juneau, Pam Galloway of Wausau, Terry Moulton of Chippewa Falls and Van Wanggaard of Racine.
Their recall campaign was spurred by anger over Walker's efforts to reduce the bargaining power of public sector unions.
The Wisconsin elections board now must verify that there are enough valid signatures, a process expected to take several months.
An election may not happen until June or later. In Wisconsin, those forcing the recall generally put up a candidate to face the official in a special election.