Pacific Northwest Regional Observatory (PNRO) is a small, professional astronomical facility located in southeastern Washington state, in the hills above the Wallula gap, midway between Walla Walla and the Kennewick-Pasco-Richland area (the "Tri-Cities").

Established in 2012, the observatory's primary instrument is the 0.8-meter telescope which had previously sat atop Rattlesnake Mountain, just west of the Tri-Cities. The telescope, and the 24-foot diameter domed building in which it is housed, are owned by the non-profit group, the Alliance for the Advancement of Science Through Astronomy.

The telescope and building were dismantled and removed from Rattlesnake Mountain in 2009, as part of the decommissioning of the Rattlesnake Mountain Observatory (RMO). Each part was attentively refurbished using facilities and resources kindly provided by Columbia Basin College (CBC) in Pasco.

The observatory is sited on land owned by Whitman College in Walla Walla. The building was constructed in the summer of 2012, and the telescope was installed later that year. Since its installation, we have upgraded the motor system and are currently in the process of calibrating the telescope for optimal performance and suitability for research and educational applications.