Oklahoma County locks people up at a higher rate than all but eight counties in the United States despite chronic overcrowding at its jail, a study released Tuesday shows.

In the past two decades, the number of people sent to county jails nationwide has nearly doubled, according to the Justice Policy Institute's study.

This has put a strain on the pocketbooks of counties, which are forced to commit bigger chunks of their budgets to deal with bulging jail populations.

The study found that the number of inmates booked into the Oklahoma County jail rose at a higher rate than bookings at every major county jail in the nation between 2001 and 2006. Oklahoma County's jail bookings rose about 53 percent during that time.

But Oklahoma County Sheriff John Whetsel said the 2,850-capacity jail's inmate population has become more manageable in the past year, thanks to a court ruling that forced the removal of several hundred state Department of Corrections inmates from county cells and new District Attorney David Prater's work to speed up prosecutions.

"It's gotten exceptionally better,” Whetsel said.

The jail's average daily inmate count is down from about 2,900 a year ago to about 2,400 in recent weeks, Whetsel said.

Still, every penny the sheriff gets from Oklahoma County's annual budget goes right to jail expenses and additional money has to be generated for other expenses, said Maj. John Waldenville, who leads the sheriff's administration bureau.

"It takes more than the county gives us to operate this place,” he said.

The sheriff's department makes most of its additional money by housing city, state and federal inmates at the jail and selling goods to the inmates while they're locked up.

Waldenville said about 78 percent of the department's annual operating budget is spent on the jail. Last fiscal year, the jail's projected operating cost was about $27 million.

County commissioners assembled a jail funding task force in 2003 in an effort to come up with solutions to the jail's funding woes. Its work has stalled, and county officials said it will likely be summer before they try to salvage the work that has been done.

Of the 38,296 bookings at the Oklahoma County jail last year, two-thirds were for drug charges, according to booking records.

Nationally, only a quarter of people jailed in 2002 faced drug charges, according to the study. But that's still a stark contrast from 1983, when about 9 percent of jail inmates faced drug charges.

The study blames poor drug enforcement policy for the dramatic rise in jail inmates. It also notes that more inmates are being held in jail for longer amounts of time before trial.

In 2006, there were 766,010 people in jails nationwide and 62 percent hadn't been convicted. The study said many inmates had been waiting long periods of time on a bogged-down justice system to give them their day in court.

Oklahoma County Public Defender Bob Ravitz said Oklahoma County officials have made a concerted effort to reduce the number of people jailed as they await trial.

Prater said he and Ravitz monitor the length of stay for pretrial inmates to ensure no one needlessly languishes in jail.

"We make every effort to keep those pretrial incarceration numbers down,” Prater said.

Ravitz said there are about 2,000 fewer such inmates in the jail than there were a couple of years ago.

"The key is staying on top of this stuff,” he said.