Wyvern Attack! (d20)

From the introduction: An adventure for four 6th to 8th level player characters...the heroes are hired by the crooked sheriff of Titan to fend off some Wyvern attacks; he suspects a villager is masterminding the attacks. In reality, the Sheriff is the mastermind, in cohorts with an evil Orcish druid, and he is trying to gain legal and actual control over an abandoned copper mine.