AUSTIN, Texas (AP) _ The ranks of the elite Texas Rangers will be joined in September by a lawman believed to be the first black to serve in the 165-year-old peacekeeping force, the Department of Public Safety says.

''I feel pretty good. It's been an ambition of mine for many years,'' said Lee Roy Young Jr., 41, a 14-year DPS veteran who currently is an investigator assigned to the criminal intelligence service in San Antonio.

DPS officers, also known as state troopers, have duties similar to state police or highway patrolmen in other states.

The Rangers, also within the DPS, are an elite force assigned to major crimes such as hostage-takings or long-standing murder investigations. They also are called on by authorities in small towns and less populated counties for help with homicides.

Rangers have a good reputation and are highly trained, DPS spokesman David Wells said Thursday. But the DPS has been dogged by charges of racial discrimination in recent years. There are five Hispanic Rangers and no women Rangers, Wells said. The National Association for the Advancement of Colored People has threatened to sue.

Michael Scott, a black state trooper from Houston, last year publicly voiced disappointment when he wasn't selected for the Rangers.

''I'm happy for Mr. Young. This is a step in right direction for him and his career. I'm disappointed for Michael Scott, because he really is the person who brought all this to bear,'' said Gary Bledsoe, president of the Austin NAACP branch.

''It appears there would be a policy in the department saying we're going to start promoting a few people because we have to, but we're going to promote people who don't complain or stand up for their rights, people who play by the rules of the game,'' Bledsoe said.

Young and three white DPS officers will join the 94-man Rangers unit in August and September, Wells said. Ranger candidates first must pass a written test. High scorers then undergo an interview by a board of six DPS supervisors.

''There's a certain mystique about the Texas Rangers. It's a highly sought- after job in the department, and many people have to apply many times - most do - before they're successful,'' said Col. Leo Gossett, DPS director.

Wells said the reason there hasn't been a black Ranger before is that Young was the first black to reach the required level in the testing. ''They're all treated the same on the testing procedures. There's no difference,'' he said.

While parts of the Rangers' history are sketchy, Young is believed to be the first black to formally be included in the ranks.

The Rangers trace their history to the days when Texas still belonged to Mexico. Stephen F. Austin in 1823 employed 10 men to serve as Rangers.

''The Texas Rangers may have been thought of as operating against Indians and Mexican raiders in the early years and later against outlaw bands, feudists, stock thieves and local rioters,'' says a history in the authoritative ''Handbook of Texas.''

In 1935, the Rangers were reorganized and placed in the DPS and now are stationed in towns across the state.