California is out of legal options in its fight to overturn court orders that require the state's overcrowded prison system to find a way to rid itself of nearly 10,000 more inmates.

In a one-line order, the U.S. Supreme Court on Tuesday rejected Gov. Jerry Brown's final legal maneuver to end federal court oversight of the nation's largest prison system, effectively forcing the state to follow through with a legislative plan to solve a decades-old prison crisis.

The justices refused to review a special three-judge panel's most recent orders requiring California to meet strict deadlines to reduce the inmate population. Now, the Brown administration must craft ways to shift inmates out of state prisons through a host of proposals, from sentencing reforms to shipping some of them out of state.

The Supreme Court earlier this year rejected California's request to stay those orders, which are the final stage in a long legal battle over prison overcrowding deemed so severe it has deprived inmates of adequate medical and mental health care.

The governor and state prison officials released a statement saying they were "disappointed the state's case won't be heard.". But they lauded the progress made in recent years in shedding nearly 30,000 inmates from state prisons, and vowed that the legislative plan they've submitted to the three federal judges "will continue to build on these landmark reforms."

Lawyers for the inmates said the Supreme Court's refusal to hear the case should force the state to act.

"(It) is a strong affirmation and message to the state: Your prisons are still dangerous and broken," said Michael Bien, an attorney challenging the prison conditions.

Last month, the three-judge panel ordered state officials and inmates' lawyers to meet on the latest legislative plan to cut about 10,000 inmates from the prisons. The governor's realignment plan has already shifted thousands of inmates to county jails, following aU.S. Supreme Court in 2011 ruling upholding the panel's orders to dramatically lower the prison population.

The panel has given the state at least until the end of January to report back to it. The governor and Legislature agreed recently to try using mental health and drug treatment programs to limit the number of inmates being sent to the state's prisons for new crimes, asking the judges to give the state three more years to meet the latest goals.

If the judges do not agree to that solution, state officials say they would spend more than $300 million to ship the inmates to private prisons and prisons in other states.

In their September order, the judges did not indicate whether they would accept that proposal but instructed state officials and inmates' advocates to focus on several inmate categories, including the elderly and juveniles, immigration violators, the seriously ill and those serving certain three-strikes sentences. The judges have previously threatened the Brown administration with contempt if they do not comply with the inmate reduction orders.

The governor sought relief from the Supreme Court this summer, arguing that California has addressed the overcrowding problem and is giving inmates adequate medical and mental health care. But the Supreme Court decided against revisiting the issue.

Howard Mintz covers legal affairs. Contact him at 408-286-0236 or follow him at Twitter.com/hmintz