IDAHO FALLS -- Rocky Mountain Power officials say electricity has been restored to more than 53,000 customers in Eastern Idaho. Earlier Wednesday, a technical problem at one of the utility's substations near Firth caused an outage that effected customers across the region. Company spokesman David Eskelsen says the company was required to disrupt service to about 49,000 Idaho customers shortly after 5 a.m. Wednesday. Bonneville Power has also asked the Fall River Rural Electric Cooperative to cut power to half of its customers in the Teton, Island Park and West Yellowstone, Mont., areas. Temperatures were in the single digits while many schools were affected by the outage. Warming shelters were opened in Rexburg, Rigby, Ammon and Idaho Falls. Fall River asked customers to continue conserving energy so the region wouldn't face rolling blackouts.