Burk, the head of National Council of Women's Organizations, flew to Atlanta on Tuesday to sign paperwork for the lawsuit, which would be filed by the Georgia chapter of the American Civil Liberties Union.
Burk applied last week for a one-day permit to have 24 protesters at Augusta National's front gate and another 200 across the street during the tournament's third round April 12.
''If they don't approve it, we will file the lawsuit immediately because it's going to be necessary to get what we need to' protest, Burk said by telephone Tuesday.
Richmond County Sheriff Ronald Strength had not issued a decision on Burk's request by late afternoon Tuesday. He did not return a request for comment.
Burk's suit would challenge whether Augusta's protest ordinance, which city officials revised last month, infringes on free-speech rights by requiring protesters to seek a permit from the sheriff at least 20 days in advance.
The sheriff can approve, deny or amend any request.
With her protest application last week, Burk included a letter threatening to sue if she did not get a favorable response by Tuesday.
Strength was expected to decide on Burk's application Wednesday. He previously said he opposed allowing protests directly in front of Augusta National during the Masters because of concerns about traffic and safety.
Burk said Augusta officials still might avoid a lawsuit if they approve her protest plans Wednesday. But she said ACLU lawyers would still need to work with city officials to iron out ''constitutional problems'' with the protest law.