Oregon has a relatively quick and easy appeal process for improperly denied public records requests. The public records act allows anyone "denied the right to inspect or to receive a copy of any public record of a state agency" to petition the denial to the Attorney General ("AG"). Which is then expected to issue an order.
The AG accepts petitions by web form, mail or email. Because public records are supposed to be accessible, the AG is generally good about accepting and giving fair consideration to informal requests. Often it is sufficient to provide a simple timeline of what happened, the text of the request, and PDF copies of any correspondence between the requester and the agency.
If the AG finds that the state agency violated the public records act they are supposed to — within seven days of the petition — order the agency to disclose the records, and may also order a fee reduction and/or a $200 penalty to be paid to the petitioner.
If the AG rules against the petitioner or fails to respond in seven days, this opens the door for the petitioner to sue the government in court to order disclosure. In such a lawsuit, the petitioner is entitled to be paid its attorney fees and costs if it prevails.
If the AG rules in favor of the petitioner, then the agency must either file suit against the petitioner to appeal the ruling or comply in full with the order. If the agency disobeys the order and does not appeal, then the petitioner may file suit, and, extraordinarily, is entitled to its attorney fees win or lose.
Below is a fairly straightforward example of a request submitted on behalf of https://twitter.com/kenklippenstein which can be used as a guide or template.