Here is another picture from Stanford Arizona garden. There are variety of Opuntias growing there, most of they happy and large. The volunteer garden maintainers have yo trim them back time by time, to keep the pathways open.
This plant is probably Opuntia engelmannii, a common plant of Texas, New Mexico and Arizona deserts. It has wide open yellow flowers and pretty fruit, perfectly eatable once you clear of glochids, but full of large seeds. In the Opuntia native land ripe fruit do not stay on the plant for long, cleared up quickly by the desert inhabitants. Down in Stanford lands ground squirrels do not venture close to the spiny plants.
Nice contrast of the vine-red fruit and pale bluish pads is what prompted me to take this image, showing the 'cactus fall colors'.