Scottsdale and Phoenix each acquired hundreds of acres of state trust land Tuesday in separate auctions that generated more than $16 million for the Arizona State Land Department.

Scottsdale was unopposed in its $6.5 million bid for 400 acres southeast of Pinnacle Peak and Alma School roads.

Phoenix was the lone bidder at $9.56 million for 295 acres southwest of the road alignments of Dove Valley Road and Seventh Street. The city plans to add the land to its Sonoran Preserve.

Mayo Clinic Hospital is seeking Phoenix's permission to put up the Valley's tallest buildings outside of central Phoenix.

Citing an aging population that will increase demand on hospitals, Mayo wants to construct a new hospital building and four outpatient clinic and office structures on its campus at 56th Street and Mayo Boulevard in northeast Phoenix. The buildings would be 250 feet high - taller than any buildings in Arizona north of Thomas Road.

The new hospital would be built east of the Residence Inn hotel, while the clinic buildings would go in east of the current specialty building on the east side of the hospital.

The increased height would allow Mayo to retain open space and would facilitate patient and technological needs better than spreading out.

In a statement, City Councilwoman Peggy Neely, citing Mayo's need "to operate with optimal efficiency and effectiveness," said she fully supports the plan.