CAISO transmission map: lines and substations
Explore public transmission lines and substations across the CAISO footprint, alongside the mapped market zones. Open the map to locate a site and inspect the infrastructure around it.
See it on the live CAISO map, updating as the market publishes.
Explore the CAISO transmission mapAbout this view
Locate CAISO transmission infrastructure
The map uses public HIFLD transmission-line and substation records across the CAISO footprint. Inspect the published names, geometry and voltage fields where available, with the mapped market zones for orientation.
Put a site in its grid context
Use the map to compare a site with nearby substations, lines and other available layers. The public inventory describes infrastructure geography; proximity to a line does not establish a connection point, available capacity or an approved interconnection.
Questions
What does this map show?
The transmission lines and substations published in the HIFLD public inventory, drawn across the CAISO footprint. It is geographic reference data — the operational network model, deliverability results, and real-time flows stay with CAISO and the participating transmission owners.
Does this show which points of interconnection are available?
No. It shows where public lines and substations are, which is where a point-of-interconnection search starts. Which points are offered and what capability they carry come from CAISO's interconnection process and transmission plan.
Does this cover all of California?
The map is framed on CAISO. Parts of California are served by other balancing authorities — LADWP, the Balancing Authority of Northern California, and the Imperial Irrigation District among them — and the public inventory there belongs to those systems.
Will the map open with these layers?
Yes. It opens the live CAISO workspace with the same transmission, substation, and zone layers and the same viewport shown on this page.