PIERRE, S.D. - South Dakotans will get more access to government records under a new law that follows the lead of most other states in presuming that documents are open unless there's a good reason to keep them secret.

Until now, people who sought government information had to prove documents were open, but as of today, the burden shifts to government to show why it is withholding something, said David Bordewyk of the South Dakota Newspaper Association.

"By giving that presumption of openness to the public, that's obviously a very fundamental change in our public records law in South Dakota," Bordewyk said.

The main sponsor of the law, Senate Republican Leader Dave Knudson of Sioux Falls, said its immediate effect will be to open more financial documents to public inspection. Over time, the law will cause local governments to be more consistent in handling records and interpreting what is open, he said.

"I think information being available to the public will have a long-term positive impact on government," Knudson said.

The 2009 Legislature passed the measure after previous attempts failed in recent years. Gov. Mike Rounds opposed a similar bill last year but supported this year's version because he said it struck a balance between opening government records and protecting the private information some agencies gather about people.

The old law provided that a government record was open only if the state, city, county, school district or other agency was required by law to keep that record. Many documents were considered confidential.

The new law starts with a presumption that records are open to public inspection, then lists the types of records that must be kept confidential.

Among them are medical and financial records, student records, trade secrets, university research secrets and security information that would endanger the public if disclosed.

One change made in the bill was requested by the Republican governor, who said some information must be protected so government officials can work effectively. That provision says information will not be released on correspondence, calendars, appointment logs, working papers and records of telephone calls of public officials and government employees.

Rounds said he and other government officials need to consult with staff members and others in private before going public with proposals or decisions. He said he would have trouble getting businesses from other states to relocate to South Dakota if he had to disclose every meeting with business owners.

The governor's press secretary, Joe Kafka, said requests for government records have not increased since the measure was passed but that may change as the new law takes effect.