The public has until 5 p.m. Sept. 21 to comment on a proposed 86-mile transmission line connecting Yuma County and California’s Imperial Valley.
The California Public Utilities Commission (CPUC) is beginning its environmental review of the Ironwood Transmission Line, a project proposing a 500-kilovolt line running from the North Gila Substation near Yuma to the Imperial Valley Substation in California.
But the project developer’s preferred route has raised concerns from the Fort Yuma Quechan Tribe.
The route would leave North Gila and travel north before crossing the Colorado River near Imperial Dam. From there, it would run west, just north of the Fort Yuma Quechan Reservation, and through the Cargo Muchacho Mountains before continuing across Imperial County.
Although the route avoids the reservation, Manfred Scott, acting chairperson for the Tribe’s cultural committee, told KAWC that the Tribe opposes the preferred route. He pointed in particular to the Cargo Muchacho Mountains, which he said are culturally and spiritually significant to the Tribe.
Instead, Scott said the Tribe wants an alternate route considered as part of the CPUC’s review.
The project developer — Horizon West Transmission — says Ironwood would strengthen the power grid around Yuma while also allowing more electricity to move into Southern California. Its routing study says the project would help address transmission constraints affecting San Diego and Los Angeles while improving reliability around Yuma.
The project began in 2023 when the California Independent System Operator (CAISO) identified a new line between the substations as part of its long-term transmission plan.
CAISO manages much of California’s electric grid and plans for new transmission infrastructure. Its board approved the Ironwood plan in 2023 and in the following year, selected Horizon West — part of Florida-based NextEra Energy — to finance, build, own and operate the line.
Horizon West filed its application with CPUC in September 2025, and the commission deemed that application complete this March.
As Horizon West developed the project, it was also meeting with the Quechan Tribe over possible routes.
Its routing study says company representatives met with Quechan officials eight times between June 2023 and April 2025.
Beginning in June 2024, tribal leaders raised concerns about routes north of the reservation, describing the area as ancestral land with deep cultural and spiritual significance. They also raised concerns about sacred mountains, possible ceremonial and burial sites and other culturally sensitive locations.
Protect Kw’tsán, a Quechan-led effort to protect the Tribe’s ancestral lands, identifies the Cargo Muchachos — known as Avi Kwa Suen — as part of a larger cultural landscape extending beyond the reservation.
The study also says known cultural resources are present along portions of the preferred corridor.
By December 2024, according to the study, the Tribal President, Tribal Council members and Cultural Committee members opposed any route north of the reservation.
The Tribe has asked Horizon West to consider routes farther south instead.
Horizon West says it did.
According to the routing study, the company expanded its search to include routes through and south of Yuma after hearing the Tribe’s concerns. These potential alternatives would have run through Yuma, along the Colorado River and near Interstate 8.
But the company ultimately concluded those routes were not viable because of a combination of existing and planned development, transportation and airport constraints, infrastructure and difficulties obtaining the necessary land rights.
That’s why Horizon West selected the route north of the reservation as its preferred option.
But Protect Kw’tsán wants the commission to take another look at the alternatives Horizon West set aside.
Protect Kw’tsán’s website provides a prewritten message for people who want to submit public comments. It specifically asks CPUC to consider three things in its environmental review:
• Fully study the alternate route requested by the Fort Yuma Quechan Indian Tribe rather than relying on Horizon West’s decision not to carry it forward. • Treat cultural resources as an ongoing part of the review, with the Tribe involved as a consulting party as the route is refined. • Reconsider the project’s purpose and need based on current conditions, including changes to geothermal and lithium projects around the Salton Sea.
The route is not final, however.
CPUC is preparing an Environmental Impact Report under the California Environmental Quality Act. The commission expects to release a draft in the third quarter of 2027, followed by a final report in early 2028. Separate approvals will also be required in Arizona and from federal agencies because portions of the project would cross federal land.
The current scoping period began Aug. 7 and ends at 5 p.m. Sept. 21. Comments can be emailed to CEQA@IronwoodTransmissionProject.com and will become part of the public record.
Protect Kw’tsán is encouraging members of the public to submit comments before the 5 p.m. deadline.
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This reporting is supported by a grant from the Arizona Local News Foundation.
