On July 13, 1909, A-Y-P Exposition guards catch six men sneaking into the exposition grounds through a manhole in a wooded area behind the Hoo-Hoo House and adjacent Natural Amphitheatre, but these freeloaders turn out to be only the tip of the iceberg. The exposition took place between June 1 and October 16, 1909, drawing more than three million people. Visitors, most of whom entered by legitimate means, came from around the state, the nation, and the world to view hundreds of educational exhibits, stroll the lushly manicured grounds, and be entertained on the Pay Streak midway, while Seattle promoted itself as a gateway to the rich resources of Alaska, the Yukon, and Asia. The illegal manhole entrance leads down to a sewer tunnel below; the exit to the tunnel is a quarter mile away, just north of the exposition grounds. The discovery solves a perplexing riddle, dubbed "the mystery of the muddy shoulders," which had plagued A-Y-P security for most of the preceding week.
A Side-Splitting Farce
"Had the late [playwright] Charles Hoyt survived to see the Alaska-Yukon-Pacific Exposition, he might have found added material for his side-splitting farce-comedy 'A Hole in the Ground' in the great sewer mystery that has just been unearthed by the exposition guards," chortled the Seattle Daily Times in a front page story on July 14, 1909. Hoyt would have had plenty of material to work with: cunning and bold young men, outwitted fair guards, and not one but three holes in the ground by which these adventurous lads got into the fair.
As luck would have it, a sewer tunnel, known as the north trunk sewer, was under construction at the same time the A-Y-P Exposition got underway on June 1, 1909. The tunnel's entrance -- which was about eight feet wide -- was just north of the exposition grounds, on the University of Washington campus above the university boat house. It was not hard to find. Even better, it was unguarded. Two or three men could easily stroll the tunnel side by side -- all they needed was a torch so they could see. Best of all, since the sewer was still under construction (though nearly finished), the tunnel was still clean.
The tunnel entered the exposition grounds in its northeast quadrant, then ran south, conveniently behind several buildings located along the eastern edge of the fairgrounds, before making a dogleg to the right at the stadium and then proceeding west until it eventually reached Lake Union. There were manholes interspersed along the tunnel every quarter mile or so, and none of the manhole covers were secured, which allowed the sneaksters to pick and choose which way they were going to get into the fair. All they had to do when they reached the exit of their choice was climb an iron ladder about 50 feet, pop the cover and viola -- a free trip to the fair!
No one ever knew how word of the mysterious "Northwest Passage," as some wags dubbed the tunnel, got out. Some speculated that a sewer worker took a trial run, bragged about it to his friends, and the deluge began. Others speculated that someone found the tunnel by chance and word spread that way. But whatever the origin, by late June word of the free route into the exposition was spreading like wildfire. The Star suggested that the tunnel was a particular favorite with the fraternity boys at the University of Washington, but it soon became a big hit with other men and boys. No women were reported to have used the tunnel, though that doesn't mean some didn't.
By the second week of July guards stationed along the eastern end of the exposition grounds were noticing an increasing number of men coming up the paths from Lake Washington, brushing dirt from their shoulders, and surmised that some of these men must be jumping or crawling under the fence that circled the exposition grounds. But an inspection of the fences showed them to all be in order with no breaks, and there was no evidence of anyone leaping over or burrowing under the fence. At first the guards considered the furtive fairgoers more a joke than a threat, but their grins vanished when A-Y-P Exposition Police Chief Charles Wappenstein advised them the fair was probably losing over $100 a day (nearly $2,000 in 2008 dollars) from the gatecrashers, and doubtlessly recommended they dig in and get to the bottom of the case.
The guards staked out the fences, patrolled the lakeshore, and lurked in dark shadows for well-nigh a week. They found nothing. At the same time the number of clandestine visitors continued to rapidly multiply. It was as if someone had knocked over a nest of bees: "Meanwhile the number of muddy shoulders increased daily, especially in the evening, and every guard in the district back of the forestry and machinery buildings reported scores of cases where he observed men coming up the paths from the Lake Washington shore, brushing dirt from their shoulders. All sorts of men were observed, some in laborers' clothes, some well dressed, some apparently young college men" (The Seattle Star).
Then, on the afternoon of July 13, a guard stumbled across a well-trodden path leading out of a wooded area behind the Hoo-Hoo House, adjacent to the Natural Amphitheatre. Investigating further, he found a manhole hidden behind some bushes, with the trail seeming to disappear into the manhole. He opened the manhole, climbed down, and at the bottom found an oil-soaked torch made from rags. He followed the tunnel a quarter mile north to its exit on the University grounds, and knew he had solved the riddle -- including the mystery of the muddy shoulders, which resulted from the men having to squeeze through the relatively narrow manhole as they climbed out of their secret subway.
To add insult to injury, fair guards found two more manholes south of the Hoo-Hoo House with well-trodden paths leading from them. The next one was behind the Michigan Building, and the other south of that, just below the railroad track near the Great Northern Railway locomotive exhibit. But the path leading from the manhole near the Hoo-Hoo House was the clear favorite, probably because it was the shortest distance from the sewer's entry north of the fairgrounds.
Now all that remained was to catch the culprits in the act. That turned out to be far easier than finding the underground passage. Chief Wappenstein assigned the team of Sergeant John Gassert and Patrolman W. White to guard the manhole near the Hoo-Hoo House. As dusk fell on the evening of July 13 the two men hid in the bushes and waited. Before it was even fully dark the guards saw the manhole cover began to shake; by and by the cover popped up and landed with a soft thunk on the ground. In the cover's place a head appeared, cautiously looking around like a turtle; mistakenly satisfied that he was safe, a young man climbed out and was promptly arrested. The guards hid again, waited a few minutes, and quickly nabbed five more offenders as they crawled out of the manhole. But as the last person was being led away another man popped up out of the manhole behind him, saw what was happening, and quick as a mole ducked back into the manhole and vanished.
The guards assumed word would get out that the jig was up and no one would try the tunnel again. Just to make sure, though, the manhole covers on the fairgrounds were clamped shut, and the sewer entrance itself was boarded up and placed under lock and key. The six errant wayfarers, all young men aged 19 and 20, were questioned and quickly confessed that the sewer tunnel had been a preferred route into the fair for perhaps 100 to 200 men daily for the past two weeks; fair officials estimated that as many as 2,000 men had entered the exposition this way. After their interrogation the delinquents were locked up until about 11 p.m. in the exposition guard room, then released with a stern warning not to do it again.