Crew works to repair Grand Canyon trail washed out by a collapsed slope in 2013.

DALLAS -- The National Park Service's backlog of deferred maintenance projects has grown to $11.5 billion, an increase of $200 million since the end of fiscal year 2013, according to the latest report.

California parks account for the largest share of the total at $1.7 billion, followed by the District of Columbia at $1.195 billion, New York at $907 million, Wyoming at $866 million, Virginia at $666 million and Arizona at $516.9 million. Washington State's backlog is $507 million, followed by North Carolina's $395 million, Maryland's $345 million, Mississippi's $335 million and Tennessee's $321 million.

Among individual parks, the largest deferred maintenance was reported at the National Mall in Washington, D.C. at $853 million, Gateway National Recreation Area in New York at $627 million, Yellowstone at $634 million, Yosemite at $553 million, and the Grand Canyon at $329 million.

Park roads and bridges account for about half of the maintenance backlog. The National Park Service receives some funding for these projects through the Federal Lands Transportation Program in the surface transportation bill. Those funds are set to expire in May.

President Obama's proposal for the transportation bill, now under consideration in Congress, includes $150 million in new funding for nationally significant projects. The money would be awarded competitively for major transportation projects on federal and tribal lands.

Grand Canyon National Park's paved roads need $116 million and water systems need $100 million, but the report said each of the nine repair categories in the park needs at least $1 million.

In Utah, Glen Canyon National Recreation Area around Lake Powell has the biggest backlog, coming in at $65.1 million. Zion National Park is not far behind with $62.1 million in delayed projects. Canyonlands' backlog totals $40 million. Bryce Canyon's is $37.6 million. And Arches' managers logged a $32 million to-do list.

In Colorado, the parks need $205 million of work, including $68 million at Rocky Mountain National Park.

In northern New Mexico, the National Park Service is preparing to add the 140-square-mile Valles Caldera park to its inventory. The New Mexico park is one of seven being added this year. A Park Service spokesman said the agency's job now is to find money within its existing budget to maintain the new park. An interim budget is due in 90 days.

While harsh winters or intense sun take a toll on infrastructure, increased tourism adds to the strain, officials said. Close to 300 million people visited the parks in 2014, breaking a record of 287.2 million set in 1987.

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