Prince George's County Fire Chief Ronald D. Blackwell grew up in Kansas City, Mo., dreaming of becoming a firefighter but never seeing anyone who looked like him riding on the firetrucks that sped past his house.

His fantasy become more tangible one day, when, as firetrucks rolled by from Station 18, five blocks from his home, an African American firefighter smiled down at Blackwell and the other children who waved from the sidewalk.

"He waved back at me and it did something for me," said Blackwell, 52. "I thought, 'That's my fireman.' "

Blackwell's three-year tenure at the helm of one of the region's busiest fire departments has been marked by an accessibility that left many residents feeling the same way -- that he was "their fireman."

He traveled to schools, community events and galas, chatting up children, residents, and movers and shakers with equal enthusiasm, said acquaintances this week when they learned that Blackwell will soon leave his post. He was also available to the men and women who worked for him, from the rookies to the highest-ranking veterans.

"I would say the two things that make people like him so much were his approachability and his effectiveness," said Capt. Chauncey Bowers, a county fire department spokesman. "He is also incredibly hardworking."

Blackwell announced on Monday that he will leave Prince George's County Aug. 20 to take the helm of the beleaguered Anne Arundel County Fire Department.

County Executive Jack B. Johnson selected Prince George's County Fire Lt. Col. Darrell Odom to serve as acting chief until a new chief is named. Odom, a Johnson campaign contributor and volunteer who retired late last year, was brought back by Johnson in April and promoted from major to lieutenant colonel. It was widely believed that Odom eventually would be elevated to chief.

"I was shocked to find out that Chief Blackwell had resigned," said Prince George's County Council Vice Chairman Samuel H. Dean (D-Mitchellville). "During the budget hearings it didn't come up that he was looking for a job. Council members who worked for him had a lot of respect for him. His leaving is a loss for the county. Hopefully, the replacement we'll get will be up to his caliber, because we should not accept anything less."

Dean's sentiment was echoed by other leaders who said they hope Johnson will select a new chief whose credentials and experience match Blackwell's.

Odom, 49, who spent 24 years on the department, is among four people Johnson mentioned as candidates for the chief's job when he announced Blackwell's resignation. Odom's appointment raised some eyebrows after it was revealed that he had faced charges dating to 1980.

D.C. Superior Court records show that Odom was found guilty in that year of two counts of simple assault and was sentenced to 10 days in jail, all of them suspended. He was also fined $300 with all but $100 suspended.

In 1982, the records show, he was charged with assault with a deadly weapon, simple assault and possession of a prohibited weapon. Authorities declined to prosecute on those charges. In 1992, Odom was charged with simple assault, with authorities again declining to prosecute.

"I want to look at it," County Council member David Harrington (D-Bladensburg) said of Odom's past, in an interview Monday night.

Blackwell will leave a department of almost 1,900 career and volunteer firefighters and paramedics who are assigned to 47 stations. The department responds to about 133,000 calls for service each year.

Blackwell's tenure was marked by high-profile events. His swearing-in was delayed by the Sept. 11, 2001, attack on the Pentagon. He was named to head a regional arson task force of local and federal fire officials after an arsonist began setting fires in Prince George's, the District and other area jurisdictions last year.

"I am still somewhat conflicted over my decision to leave Prince George's County, a place I have come to dearly love," Blackwell said. "But I see an opportunity with tremendous potential in neighboring Anne Arundel County, and while there is never a good time to leave, I believe now is the right time to leave."

Anne Arundel County Executive Janet S. Owens (D) called Blackwell's appointment "a coup." Her county's fire department, which was recently the subject of an investigation because of spending on overtime, has 720 firefighters and 27 fire stations and receives about 86,000 calls for service annually. The former chief, Roger Simonds Sr., was asked to resign in March after questions were raised about his leadership style and overtime spending, which county officials said exceeded the county budget by $600,000.

Owens credited Blackwell for his "sense of stability, confidence and competence."

"The department has been through a lot," Owens said. "We just need to build on our own strength, settle down and go back to work."

Blackwell will take with him to Anne Arundel nearly 30 years of experience. Before arriving in Prince George's as a lieutenant colonel, essentially a deputy chief, Blackwell worked as a firefighter for 23 years in Wichita. Before joining the Wichita Fire Department in 1975, he briefly held a dual position as a firefighter and police officer with the Wichita Airport Authority. He also served in the Air Force as a fire protection specialist.

Blackwell said he plans to continue to live in Prince George's with his wife of 28 years, Diane, and their grown children, Melita and Daren. They also have a grown son, Brien, who lives in Kansas City.

He is looking forward to meeting with his new staff to assess Anne Arundel's needs and establish a game plan. And he plans to continue his trademark accessibility.

"It is important for young people to see people who have achieved on some level and to aspire to those kinds of positions," he said. "When I saw that guy on the firetruck all those years ago, he wasn't making a conscious effort, but just seeing him did something for me. I want to do that for others."

Staff writer Jamie Stockwell contributed to this article.

Prince George's County Fire Chief Ronald D. Blackwell is leaving for a similar post in Anne Arundel County.