Wind-whipped fires roared across hundreds of thousands of acres of grazing land and forest in Idaho, Oregon, Montana, Nevada and Utah after two nights of lightning storms, and houses were threatened in southwestern Idaho. The U.S. Forest Service said it hoped to have as many as 8,000 firefighters and support personnel in several national forests in eastern Oregon alone by today. Gov. John V. Evans of Idaho declared a state of emergency and ordered the National Guard to help fire crews. More than 500 fires were reported burning on 535,000 acres of forest and rangelands in the five Western states, according to the national fire command post in Boise, Ida.