Samuel Ellison Neel, 90, a former lawyer for the Mortgage Bankers Association of America and a Fairfax County government official, died June 21 of heart disease at Halquist Memorial Inpatient Center, a hospice in Arlington. He lived in McLean.

As a lawyer, Mr. Neel held a number of positions and was an advocate for mortgage banking interests in Washington since the 1930s. He also had a private law practice for decades, and from 1969 to 1978, he was a principal in the Washington firm of Neel and Siegler. He continued to have private clients until two years ago.

As chief Washington counsel for the Mortgage Bankers Association from 1946 to 1974, he frequently testified before Congress and worked with federal agencies on matters related to banking, currency and housing.

As the first chairman of the Fairfax County Water Authority, from 1957 to 1963, he helped prevent the federal government from evicting residents who lived near the Langley headquarters of the CIA. He also was chairman of the Fairfax County Redevelopment and Housing Authority in the early 1970s.

Mr. Neel was born in Kansas City, Mo., and graduated from Westminster College in Fulton, Mo. After receiving a law degree from Yale University in 1938, he came to Washington as an assistant federal prosecutor in the Justice Department's antitrust division.

Before the outbreak of World War II, he joined the Navy, and he was stationed at Pearl Harbor at the time of the Japanese attack on the base on Dec. 7, 1941. He was a lieutenant commander assigned to the staff of Adm. John Towers, an early leader in naval aviation. After the war, Mr. Neel was part of an Allied commission sent to oversee the disarmament of Japan.

Mr. Neel's roommate in the Navy was James W. Rouse, who became known as the developer of Columbia and other residential and commercial projects across the country. Mr. Neel was an early investor in the Rouse Co., and from 1967 to 1983, he was a member of the company's board.

As chairman of the Committee for Preserving the Potomac, he helped block the development of an unspoiled tract of land in Fairfax County near Chain Bridge. He also was a board member of several other not-for-profit groups, including the Episcopal Home of Washington and the Neel Foundation, a family charitable trust.

He had a lifelong interest in the outdoors and helped conservation groups preserve land in New Hampshire and Montana for public use.

He also helped engineer the release of the nation's first wildlife conservation stamps in 1956, depicting the wild turkey, the pronghorn and the king salmon. Through a friend, Mr. Neel was able to get the ear of President Dwight D. Eisenhower and recommend that the stamp project be undertaken by the Post Office Department.

At his second home in Maine, Mr. Neel enjoyed sailing his 42-foot wooden sailboat on Penobscot Bay. In 1996, when he was 82, he fulfilled a lifelong ambition by embarking on a three-week horseback journey through the wilderness of British Columbia.

A son, Wilson Neel, died in infancy in 1947.

Survivors include his wife of 62 years, Mary Wilson Neel of McLean; five children, James Neel of Croton-on-Hudson, N.Y., Amy Neel of Cloverdale, Calif., Wendy Ellsworth of Quakertown, Pa., Mary West of New Vineyard, Maine, and Sophia Kountz of Vienna; 11 grandchildren; and a great-granddaughter.

Samuel E. Neel was an advocate for mortgage banking interests.