There are two discussions going on. The discussion to answer the literal question about big trees, and the discussion to answer the real question about privacy. They are very different questions. Dealing with the privacy question, what are the moundy green things in this picture? And who do they belong to? My guess is they are white pines belonging to the neighbor. In other words, the neighbor has already planted a native evergreen capable of getting to 100 ft, and doing it extremely quickly. Any other potentially large tree is going to compete with that tree line and slow both of them down. This privacy issue would benefit most from Calliope's solution. A small tree or large shrub planted directly between the neighbor's house and the window would provide privacy without closing in the whole area. Even during the winter, densely branching deciduous shrubs can work. The front yard is going to be the trickiest one. Planting a wall of big evergreens is just going to be like building a big wall. A better idea would be planting something that was large enough to block the lower houses, but short enough to still allow views of the hills across the valley. Unfortunately, spring is the busy season for landscapers and landscape designers. People have been arranging for their services all winter, and now is the time for them to start to deliver.

We moved to this house five years ago. There was a huge spruce tree on the property. The first spring, my friend gave me about twenty violets and twenty lily of the valley. By the next summer, the violets completely covered the big area under the tree, the lily of the valley did not do as well. I did not clear the tons of needles or pinecones before planting. I just dug a hole and stuck a plant in. Done. The violets bloom each year in the early summer and remain green until winter. The plants completely disappear in the fall and come back up each spring with no effort on my part. You can't see the ground for the violets. One word of caution, you will have to make sure they do not get into your lawn or flowerbeds. They will spread wherever they can.

I just wanted to tell you that several years ago we had a huge pine tree that was near the road at the end of the driveway. Not sure what happened first - the lightning that struck it or the pine beetles that you could hear inside the tree. The top half was dead but the bottom was still alive, you could see the streak running down the tree. We live on a rural road with traffic wizzing by faster than they should so was worried the tree would fall over the road & cause an accident. Called the insurance company & since it was an act of God, they wrote us a check. My husband got some pulpwood guy to cut it down & he took it to the sawmill. Problem was, he didn't clean up his mess & left a huge part of the tree right in the driveway. My neighbor had to take his tractor & push it out of the way because the school bus uses the driveway to turn around. We spent over a year cutting chunks off with a chainsaw & burning it & finally hauled some out into the woods behind the house. Used it for lighter pine after a couple of years for the wood heater.

Your extension office is spot on. The holes are definitely from sapsuckers which open up the probability for Sequoia mouth. The tree is Shore pine (Pinus contorta) which is extremely susceptible to both. Being native trees, they do not want summer water. They are evolved to tolerate our summer drought. It's normal. I don't think sycamore will work in southern Oregon; it has totally different climate preferences. Look around. Oregon white oak (Quercus garryana) performs magnificently there and in time will become a huge majestic tree.