Idaho Power has under construction a 138-kV transmission line upgrade from 69-kV between Council, Idaho to McCall, Idaho and on to Lake Fork, Idaho as part of an overall 138-kV project to serve increasing electric demand in the Cambridge, Council, New Meadows and McCall areas. The project includes two new substations: one the 230/138-kV Horse Flat Substation near Cambridge, and 138/69-kV Starkey Substation north of Council, both completed in 2006. Known as the McCall Loop, the existing lines can not provide the power required for peak demand if an outage occurs on its sole 138-kV transmission line which runs from the Oxbow generating station in Hells Canyon to McCall. As a result Idaho Power customers on the McCall Loop have experienced outages particularly during high winds and heavy snows.

The Council to McCall upgrade from 69-kV to 138-kV from the Starkey substation to McCall substation uses H-frame and single pole construction and is under construction and expected to be operational by November, 2007. The McCall to Lake Fork upgrade coverts an existing 69-kV line to 138-kV on H-frame and single poles. This segment is planned to be constructed by August 2007.