Key developments involving the Arctic National Wildlife Refuge in Alaska.

1960 — President Eisenhower establishes the 9.5 million acre Arctic National Wildlife Range in northeastern Alaska, a year after Alaska statehood.

1980 — Congress expands the range to 19.6 million acres, renaming it the Arctic National Wildlife Refuge. It is signed by President Carter. As part of a compromise, the refuge's 1.5 million acre coastal plain was set aside for further study, leaving it to Congress to decide its future use.

1989 — Legislation begins moving through Congress to allow development of the ANWR coastal plain's oil resources, but it is brought to a halt by Exxon Valdez oil spill in March.

1991 — An energy bill includes refuge drilling, but is blocked by a Democratic-led filibuster in the Senate.

1995 — Congress passes a budget reconciliation bill that includes drilling in the refuge, but it is vetoed by President Clinton.

2001 — President Bush in his energy proposal calls development of ANWR's oil essential to meet U.S. energy needs. The House passes an energy bill that includes ANWR drilling.

2002 (April 18) — Senate rejects amendment to an energy bill that would allow development of the refuge's oil as pro-drilling forces fell 14 votes short of the 60 needed to break a filibuster.