Once again, Going-to-the-Sun Road tops the list for Glacier National Park’s deferred maintenance backlog — now sitting at $179.8 million, according to a report released Friday by the National Park Service.

Deferred maintenance refers to the cost of necessary work the park has been forced to put off or delay.

Glacier’s unfunded maintenance grew by about $1.3 million since last year. Nationwide, the park system added $440 million in unfunded maintenance obligations since last year, bringing the U.S. total to $11.9 billion.

Yellowstone National Park has more than $631.7 million in deferred maintenance.

“It’s just like a home — you only have the time and resources to do so much,” Glacier Park spokeswoman Denise Germann said Friday. “One of the biggest issues is funding available for deferred maintenance projects.”

Glacier’s total budget increased slightly from last year, to $13.6 million for the 2016 fiscal year. Its 2015 budget was $13.4 million.

Paved roads in the park account for the lion’s share of the backlog at $123.5 million. That obligation has grown by about $8 million since last year.

Germann said the park will wrap up its ongoing rehabilitation of Going-to-the-Sun Road by next year or early 2018. The final phase of the decade-long project includes this year’s replacement of the St. Mary entrance station and road work from Logan Creek to West Glacier, slated to start next spring.

Another $27.6 million is needed for building maintenance, nearly identical to the figure reported last year. The park is chipping away at that bill with the ongoing rehabilitation of the Many Glacier Hotel, which is currently in its final phase.

Deferred maintenance on the park’s 725-mile trail system accounts for $11.2 million, an improvement over the $13.6 million reported last year.

Last summer, the park worked with local partners including the Glacier National Park Conservancy and Montana Conservation Corps to repair popular thoroughfares including the Highline and Hidden Lake trails and the Trail of the Cedars.

Other ongoing work around Glacier includes replacing decades-old, inefficient windows and doors on buildings that house park employees, working on interpretive exhibits and upgrading electrical systems.

Reporter Sam Wilson can be reached at 758-4407 or by email at swilson@dailyinterlake.com.