b'E N E R G YArrowrock Dam (15 MW) Bulk Power Transmission UtilitiesArrowrock Dam is a concrete arch dam on the Idaho Power CompanyBoise River located on the border between BoiseNatural GasCounty and Elmore County.Horseshoe Bend (9.5 MW)There is little or no natural gas service in Boise County. Horseshoe Bend is a run-of-river hydroelectric Propane serviced by AmeriGas Propane (Garden facility located on the Payette River, approximatelyValley), Valley Wide Cooperative (Garden Valley), 40 miles north of Boise. and Salmon River Propane (Challis, Mackay, and Salmon).FIGURE 3. Boise County Energy Infrastructure MapBOISE County 219'