U.S. Attorney Melinda Haag of Northern California will leave her post on Sept. 1.
Haag, who was appointed by President Obama in 2010, announced her departure to her staff and to the federal judges of the Northern District of California in San Francisco.
The U.S. attorney supervises federal criminal prosecutions and civil litigation concerning the federal government in a district that includes the Bay Area and northern coastal California from Monterey to the Oregon border.
The office currently has 131 lawyers at its San Francisco headquarters and San Jose and Oakland branches.
Haag's successor will be appointed by the president and must be confirmed by the Senate.
Haag's office spokesman Abraham Simmons said that until the successor is in place, First Assistant U.S. Attorney Brian Stretch will serve as acting U.S. attorney.
Federal crimes prosecuted by the U.S. Attorney's Office include white-collar crimes, drug trafficking, bank fraud, human trafficking, intellectual property theft and environmental violations.
Beginning in 2011, Haag joined the three other regional U.S. attorneys in California in cracking down on medical marijuana dispensaries perceived to be large-scale commercial enterprises. Federal laws criminalizing marijuana make no exception for state laws allowing medical marijuana use, such as California's Compassionate Use Act.
Before being appointed U.S. attorney, Haag spent seven years as a partner in a private law firm and nine years as an assistant U.S. attorney in San Francisco and Los Angeles.
Simmons said Haag "is planning to take time off with her family" before deciding on her next step.