This weekend, crowds are expected to pack into Astoria, where the city will celebrate one of the most important milestones its ever seen: the 50th anniversary of the Astoria-Megler Bridge.

When it first opened on August 27, 1966, some 30,000 people came to Astoria to mark the occasion. The bridge - the longest continuous truss bridge in North America - came after decades of slogging through the legislative process in both Oregon and Washington, briefly derided as a "bridge to nowhere."

But that history faded quickly as tourists crossed the bridge in droves, continuing through Astoria on their drive up the Oregon Coast Highway, helping revive the economy in Clatsop County on their way.

A rededication ceremony will mark the anniversary this Saturday, Aug. 13, at 9 a.m. at Maritime Memorial Park in Astoria, in the middle of the five-day Astoria Regatta celebration.

Few would doubt the importance of the bridge today, and looking through history, it's strange to think it was doubted at all. The bridge marked a major milestone in regional travel, but also marked one of the Pacific Northwest's final and most triumphant victories: conquering the mighty Columbia River.

Graveyard of the Pacific

Since the 16th century, Europe's greatest explorers sailed up and down the Pacific coast, trying in vain to discover the big, mythical river that poured into the ocean.

The mouth of the Columbia was deceiving, and dangerous to boot. Some explorers couldn't see it at all, and those who did find it hesitated to enter. Finally, in 1792, Robert Gray successfully navigated the river and named it after his ship, Columbia Rediviva - days after Capt. George Vancouver passed it by.

But though discovered, the Columbia River remained a difficult place to settle. In 1810, a band of American settlers tried to establish a town 40 miles upriver, but were quickly deterred by floods and conflicts with local tribes. John Jacob Astor founded Fort Astoria at the mouth of the Columbia, but abandoned it only two years later.

Eventually, European explorers settled in, but the mouth of the river - known as the Columbia Bar - still remains one of the world's most dangerous passages.

Plenty of ships pass through the mouth of the Columbia, but each must hire a Columbia River Bar Pilot, licensed by the state of Oregon to navigate the difficult channel. The precaution was born of necessity - since 1792, some 2,000 ships have sunk there, earning it the nickname, "Graveyard of the Pacific."

It was an absolutely beautiful location, but the wild Columbia made Astoria a dead end along the Oregon coast.

Crossing the Columbia

Undeterred and driven by need, Astoria captain S.F. "Fritz" Elving started building ferries to take passengers and automobiles across to Megler, Wash. in 1921. His fleet grew with the automobile boom, but it couldn't keep up with growing demands. Ferries didn't run in bad weather, and the 30-minute trip caused huge backups as auto travel become more popular.

Talk of a bridge had bounced around since the 1930s, but it didn't get serious until 1953, after a summer marred by long waits for the Astoria ferry service. Two years later the Port of Astoria unveiled the design for the Astoria-Megler Bridge, kicking off a campaign to find the $24 million to build it.

Public support was broad, and the need appeared urgent, but by the 1960s the bridge's fate was still uncertain.

"A four-mile bridge to span the mouth of the Columbia River appeared as close to construction Saturday as it was when first proposed nearly 30 years ago," the Oregonian wrote after a two-state legislative meeting in 1961.

Oregon legislators had approved the bridge construction in 1959, providing that Washington split the cost 50-50. Washington legislators responded with a 75-25 offer, seeing little benefit in connecting the coastline. A bridge toll would offset the cost, but Washington lawmakers were dead set against anything with a toll, the Oregonian reported.

But despite the opposition, the plan soon gained approval on both sides of the Columbia, and in 1962, construction officially began. Finally, in 1966, the Astoria-Megler Bridge opened to the public, charging $1.50 per car in toll.

"It is a real symbol of the greatness of the Lower Columbia River and a real tribute to those who dreamed this dream and realized an ambition," Oregon Gov. Mark O. Hatfield said at the dedication. "It is an answer to the scoffers who jeered the idea from the start."

"They said it couldn't be done" was the rallying cry at the opening of the bridge, and today its existence is still a source of pride for Astoria.

"The opening of the bridge was a big deal for coastal communities at the mouth of the Columbia River," Betsy Millard, executive director of the Columbia Pacific Heritage Museum, said in advance of the rededication. "Though nicknamed the 'Bridge to Nowhere,' the Washington terminus is an area rich in history."

--Jamie Hale | jhale@oregonian.com | @HaleJamesB