Someone traveling alone(主语)//（条件状语）,if hungry,injured,or ill,//（谓语）often had //nowhere to turn //（状语）except to the nearest cabin or settlement

=Someone travelling alone , if (he was省略) hungry,injured or ill,often had nowhere to turn except to the nearest cabin or settlement

=(主语)Someone //（修饰主语后置定语;现在分词作后置定语）travelling alone//（频度状语）// often//（谓语） had nowhere to turn except to the nearest cabin or settlement  if (he was省略) hungry,injured or ill

参考译文：独自旅行的人，如果饿了，受伤了，或者生病了，除了去最近的小屋或者是安置点地之外，常常没有地方可以去。