When it comes to sacred cows in the oh-so-green state of Washington, the holiest of holies is Puget Sound, the shimmering estuary with oysters, clams and soul-stirring views for the nearly 4 million people who live around its waters.

So when Sen. Ted Stevens (R-Alaska) introduced a bill this month that would increase oil tanker traffic in the sound, nearly every state politician -- Democrat and Republican alike -- joined hands, rushed to the legislative barricades and howled with indignant fury.

Leaked e-mails from BP stoked their indignation. BP owns the largest oil refinery in Puget Sound, is a major player in Alaska's oil industry and has been a significant contributor to Stevens's political campaigns.

The e-mails, which BP says are genuine, show that the company has worked with Stevens this year, as well as with Republicans in the House, to pry open Puget Sound for more tanker traffic. One e-mail from BP spokesman Bill Kidd predicted on Oct. 19 that Stevens would soon be on the Senate floor to introduce a bill to increase refining capacity in the sound. Three weeks later, Stevens introduced his bill, saying it would "enable us to get petroleum resources to West Coast states quickly."

In the state of Washington, no one has howled louder about Stevens's bill -- and has more to gain from voter awareness of the noise she is making -- than Sen. Maria Cantwell (D-Wash.).

The first-term senator is up for reelection next fall, has a formidable Republican challenger and has been described by some political analysts as "beatable." But she has won effusive praise from local editorial writers and political veterans for standing up to the powerful senior senator from Alaska.

"This is a great issue for Maria," said Rep. Norman D. Dicks (D-Wash.), a senior member of the state's congressional delegation. "The only thing more holy in this state than keeping Californians from taking water from the Columbia River is protecting Puget Sound."

Cantwell has made a none-too-subtle reference to the nation's worst oil spill, which occurred in the waters of Stevens's home state after the Exxon Valdez ran aground in 1989.

"We learned valuable lessons when nearly 11 million gallons of oil spilled in Alaska's Prince William Sound," Cantwell said. "We don't need to relearn them in Puget Sound."

Forced by Cantwell's headline-grabbing objections, her likely Republican opponent in next year's Senate race, Mike McGavick, met with Stevens on Nov. 15 and, as he informed reporters later, told the senator that his bill is a "nonstarter" in Washington state.

Cantwell, meanwhile, has had some testy exchanges with Stevens, chairman of the Commerce Committee. He angrily cut her off during a recent hearing with oil industry executives, when she insisted that they be sworn in before testifying.

It has been an exasperating autumn for Stevens. Once again, his effort to open the Arctic National Wildlife Refuge for oil drilling has stalled in Congress. Stevens said earlier in the year that he had seen a doctor because he was "depressed" by his failure to open up the refuge.

In October, Stevens threatened to quit the Senate if funding were cut for two costly bridges in his home state. Derided as "Bridges to Nowhere," the projects have become nationally known as symbols of pork-barrel spending run amok.

In challenging Stevens, Cantwell has repeatedly invoked the sainted name (in Washington state, anyway) of the late senator Warren G. Magnuson, who in his era was as powerful -- and shameless at dishing out pork -- as Stevens is now.

In addition to Magnuson's enormous servings of legislative largess, which in the 1960s and '70s helped make Washington one of the nation's largest per-capita recipients of federal spending, the senator delivered a unique Puget Sound-protection gift to his constituents in 1977.

It came in the form of an amendment to the Marine Mammal Protection Act. The amendment imposed de facto limits on oil tanker traffic in Puget Sound by restricting the expansion of refinery terminals or docks in the sound, unless needed by consumers who live in Washington state.

After 28 years, the Magnuson amendment is strangling the ability of oil companies to supply gasoline to the growing population of the entire Pacific Northwest, according to Stevens and BP.

"Due to current restrictions," Stevens said when he introduced his bill, "it is almost impossible for companies to expand their refineries to increase supply."

BP says that oil demand on the West Coast is increasing at 2 percent a year and that there is a structural shortage of gasoline and jet fuel of about 150,000 barrels of day.

Expansion of BP's Cherry Point refinery in Puget Sound, which was built in 1971 and was the last oil refinery built on the West Coast, would greatly help ease this shortage, said Kidd, the company spokesman.

"We have a responsibility to point out that these kind of policies [the Magnuson amendment] are part of the reason why we don't have adequate refining capacity in this nation," Kidd said.

Be that as it may, Cantwell appears to be pinning her reputation -- and perhaps her reelection -- on stopping Stevens. In a letter to Sen. Bill Frist (R-Tenn.), the majority leader, she wrote: "I will use every procedural option granted to me as a United States senator to stop this unfortunate and misguided legislation from becoming law."

A Washington state ferry emerges from a fog bank on Puget Sound as the Olympic Mountains are seen above. Sen. Ted Stevens (R-Alaska) has introduced a bill to open up the sound to more oil tanker traffic, which Sen. Maria Cantwell (D-Wash.), who is up for reelection, opposes.