Puebla governor Martha Erika Alonso died along with her husband a senator and former governor, in a fatal helicopter crash.
The aircraft carrying Alonso and Moreno Valle came down shortly after it took off.
The two pilots were killed. Reports say a third passenger also died.
Moreno was governor of Puebla between 2011 and 2017.
The couple was headed to Mexico City, Mexico's Communications and Transportation Secretary Javier Jimenez Espriu said. He said Mexican Civil Aviation authorities are at the scene of the accident to further investigate the cause.
According to the local constitution, the state legislature will have to appoint an interim governor and to call an extraordinary vote that must be held in three to five months.