d_l it is never that simple. Oregon is a mountainous tree filled state which receives massive amounts of water. The water saturates soil making it very prone to landslides. They have very large stands of Douglas firs with interwoven roots. The Dougs on the edge are more prone to fall. Powerlines come in leaving a line of weakened Dougs right in harms way. This is fine even with the snow but when it is followed by rain, the rain saturates the snow, weighing down the edge trees. I could go on but I think you get the idea. Power companies in recent history have replaced lines with cable that looks like you could tow the Titanic with. I have personally observed these newer lines holding up extremely heavy snow ladden Dougs All the line renovations cost allot of money the public has to pay for....