The planned transmission 550-mile line (890 km) would connect the SunZia wind farm in central New Mexico to Pinal county in south-central Arizona.

It would consist of two 525 kV high-voltage direct current (HVDC) transmission lines with a total capacity of 3,000 MW of electrical power.

Environmentalists opposed the project, concerned about the line passing through the San Pedro River (Arizona) Valley and fearing that it might be used to transfer fossil-fuel generated electricity.

[12][13][14] Pattern Energy bought the SunZia transmission line project from SouthWestern Power Group in July 2022.

[17] In November 2023, the Bureau of Land Management temporarily halted work on the project due to concerns of the Tohono O'odham Nation and the San Carlos Apache Tribe that the project damages religious and cultural sites in a 50-mile portion (80 km) of the San Pedro Valley in southwestern Arizona,[18] but lifted the suspension later that month, allowing work to resume.

[20] The plaintiff stated that the Arizona Corporation Commission (ACC) failed to adequately consider dramatic changes in the SunZia project when granting the amended Certificate.

[28] The legislators asked the Commission to review their previous actions and ensure that the concerns of Arizona ratepayers are adequately addressed.