Umatilla County

A facility drawing hundreds of megawatts connects at bulk transmission voltage, so the second figure matters more than the first: forty 69 kV yards are not a substitute for one 500 kV substation. 2 of the plants here carry no capacity tag, so the megawatt total is a floor rather than the region's output.

Proximity is not connection. Nothing here shows that any facility has contracted power from any of these substations. That gets settled in interconnection filings Helios cannot read, and in several regions those queues now run for years. A county showing no substations may have none mapped rather than none standing.

“First mapped” is when OpenStreetMap recorded the facility, not when it was built — OpenStreetMap carries no construction dates. Mapped area means a building floor plate, campus boundary, or construction polygon according to the “Mapped as” column; those quantities are never added together. The megawatt column appears only for buildings and is their floor-area share of a reported national total, not a measurement.