[1] Walkup was first elected on November 2, 1999, defeating Democratic former City Councilwoman Molly McKasson and local businessman Bob Beaudry.

He phoned every hospital in the city and hosted a meeting at his office, where plans were formulated for a new world class trauma center, opened on January 8, 2008.

[3] He oversaw Tucson's resumption of using Colorado River water in 2001, which was suspended in the 1990s after it corroded residents' pipes.

[2] Walkup was re-elected for a second term November 4, 2003, narrowly defeating Democratic former mayor Tom Volgy.

Mayors Climate Protection Agreement and presided over the development of Tucson's solar energy capability.

He introduced fees for waste collection and for development impact, and shifted the library system to the county.