The 16-day government shutdown in October came at a $414 million economic loss to communities that host and surround national parks, the Interior Department said Monday.

Those figures are a preliminary estimate based on 7.88 million fewer park visitors in October compared with the previous three years. In the runup to the Tuesday release of President Obama's fiscal 2015 budget proposal, the announcement serves as ammunition for the commitment to parks funding that Interior Secretary Sally Jewell has sought.

"[O]ur national parks help propel our nation's economy, drawing hundreds of millions of visitors every year who are the lifeblood of the hotels, restaurants, outfitters and other local businesses that depend on a vibrant and reliable tourism and outdoor recreation industry supported by our public lands,” Jewell said.

Environmental groups have indicated they plan to press Republicans during the 2014 midterm cycle on the shutdown, especially when it comes to parks. Polls have shown that a majority of voters blamed House GOP lawmakers for the shutdown, though many Republicans pointed fingers at the White House.

Jewell has blasted Republicans as well, as the shutdown hurt the National Park Service's 16,000 employees. She has pushed the House to adequately fund the agency -- the spending bill passed in January awarded it $2.6 billion, though the House had originally proposed $2.3 billion.

The Obama administration has pushed the national parks as an economic driver. The Interior Department released a separate report Monday showing that the parks generated $26.75 billion in revenue while supporting 243,000 jobs -- more than 200,000 of which were in neighboring communities -- in 2012. That amounted to $10 in benefits for every dollar spent, noted National Park Service Director Jonathan Jarvis.

Obama also has stumped for national parks and conservation, as he said in his State of the Union address that he would act unilaterally to protect more wilderness if Congress doesn't.

Some progress is being made on that front. The House is scheduled to vote this week on a Senate-passed bill that would conserve an additional 32,500 acres of Lake Michigan shoreline at the Sleeping Bear Dunes National Lakeshore in Glen Arbor, Mich. If it clears the lower chamber, it would be the first conservation bill to reach Obama's desk since 2010.