u/Diligent-Bunch-260

Noticed parts seemed to be ‘dying’ at end of last Fall. Spring is here and bare in spots. Maybe it’s my bias, but individual leaves don’t seem as robust as past years. (Has had some sort of sticky leaf pest occasionally past several years). Circumference = 90 inches / 230 cm. Guesstimated height is 35 ft / 10+ m. House built in 1962, so oldest it could be is 60-ish. Not a standard lot tree, so also not sure when originally planted. Had some ‘thinning’ done maybe 10 years ago. Nearby plants watered by drip line 3x week. Located in Contra Costa County, Northern California. Thanks for any insights. Love this tree. But wondering if I need to start seriously thinking about next steps.