The regional Haze Rule sets a 60 year timeline for states to improve visibility within mandatory federal Class I areas from Baseline (2000-04) levels to Natural Conditions by 2064. States are required to show that Reasonable Progress is expected to be made toward this goal over the course of intermediary planning periods. Reasonable Progress is defined by the EPA both in terms of what can be measured and projected using current scientific understanding, and, when reviewing controls for existing facilities, specific compliance-related statutory factors. WRAP has developed a protocol to address the technical requirements of determining Reasonable Progress, based on existing EPA guidance and recommendations from WRAP forums and workgroups. The resources on this page are intended to support these technical requirements.