A big part of Monroe's history has been lifted away from its place over the Skykomish River.

"Jumping off the trestle has been a rite of passage out here," said Mayor Donnetta Walser, as she watched a 100-ton steel truss lifted into the air last week. The trusses had spanned the river since 1969.

Some parts of the span had been removed earlier. One section was lifted away by a crane last week, and the remaining trusses are expected to be removed by the end of the month, the state Department of Natural Resources (DNR) said.

The former railroad line, running south to Duvall and other destinations, dated to about 1900, and a covered railroad bridge was built over the river in 1911. In 1939, according to the Monroe Historical Society, that bridge was replaced by a 450-foot covered bridge that was the longest covered railroad bridge in the world and the longest covered bridge of any kind in the Western U.S.

The covered span was replaced in 1969 by the steel bridge, which was later abandoned by the Milwaukee Road. The tracks were last used in the 1970s, said Bob Wieneke, 67, a lifelong Monroe resident who attended last week's demolition.

After the abandonment, the line fell to other private owners, but the history is unclear.

"No one knows who really owns it," said Bill Sayer, the vice president of aggregates for Cadman, which operates quarries in the area and is paying for the demolition as the ostensible owner of the span.

Though generations of Monroe kids had jumped from the bridge, in recent years it had become a significant hazard, said Dave Roberts, an assistant district manager for the DNR.

One danger came from the continuing public access, bringing risks of injury, drowning and other dangers, including fire. Wooden trestle supports were charred from fires set by vandals, Roberts noted.

A second risk was that the bridge might collapse in a flood, trapping logs and other debris and causing extensive flood damage, he added. Much of the piling supporting the trusses had been eroded by floods.

The DNR is involved because of its role under state law as having the stewardship for rivers, noted Doug Sutherland, the state commissioner of public lands, one of several political leaders who attended last week's removal.

Sayer said the cost of the demolition would be in "seven figures," with Cadman paying most of the expense, although the DNR and other public agencies have helped with permits and other steps.

Snohomish County Executive Aaron Reardon estimated it has cost the county about $35,000 to speed permitting so the work could be done within a two-month "fish window" to avoid disrupting fish runs.

A crane is being used to lift the sections onto trucks, and the trusses will be cut up and recycled.

Each truss is about 120 feet long and weighs 80 to 100 tons.

Peyton Whitely: 206-464-2259 or pwhitely@seattletimes.com