quercus macrocarpa

branch from below
Quercus macrocarpa is cultivated by plant nurseries for use in gardens, in parks, and on urban sidewalks. Bur oak makes an outstanding ornamental tree. Among the white oaks, it is one of the most tolerant of urban conditions, and is one of the fastest-growing of the group. It has been planted in many climates, ranging northwards to Anchorage, Alaska, and as far south as Mission, Texas. It withstands chinook conditions in Calgary, Alberta.–wikipedia

Big acorns on the downtown mall.