East Tucson is relatively new compared to other parts of the city, developed between the 1950s and the 1970s,[citation needed] with developments such as Desert Palms Park. It is generally classified as the area of the city east of Swan Road, with above-average real estate values relative to the rest of the city. The area includes urban and suburban development near the Rincon Mountains. East Tucson includes Saguaro National Park East. Tucson's "Restaurant Row" is also located on the east side, along with a significant corporate and financial presence. Restaurant Row is sandwiched by three of Tucson's storied Neighborhoods: Harold Bell Wright Estates, named after the famous author's ranch which occupied some of that area prior to the depression; the Tucson Country Club (the third to bear the name Tucson Country Club), and the Dorado Country Club. Tucson's largest office building is 5151 East Broadway in east Tucson, completed in 1975. The first phases of Williams Centre, a mixed-use, master-planned development on Broadway near Craycroft Road, were opened in 1987. Park Place, a recently renovated shopping center, is also located along Broadway (west of Wilmot Road).
When was East Tucson developed? (If the question is unanswerable, say "unanswerable")
between the 1950s and the 1970s