Russell Abt, owner of Arbor Tree Care, whistles a tune as he positions himself in the Pine Tavern tree. He inspects the tree regularly, climbing and removing hazardous limbs as necessary.

First, a little history: For more than 20 years after the Pine Tavern’s opening in 1936, diners enjoyed views of the Deschutes River in the distance, along with two old pine trees that stood close by, in the eatery’s backyard. In 1957, the restaurant added on — and brought part of the view indoors, enclosing the trunks of the two pines in its new garden room. In 1983, the smaller of the trees died of pine beetles, leaving just its trunk. The older tree, thought to be more than 150 years old, is in reasonable health for its age, but it must be cared for daily.