With the National Park System’s (NPS) centennial anniversary approaching in August, President Barack Obama has proposed spending more than $1 billion restoring the parks. Unfortunately, that won’t come close to covering the $12 billion needed to pay for NPS’ deferred maintenance (DM) nationwide.

“Deferred maintenance is necessary work performed on infrastructure—such as roads, bridges, visitor centers, trails, and campgrounds—that has been delayed for more than one year,” says NPS Public Affairs Specialist Vanessa Lacayo. And within that $12 billion, there’s a more serious classification called Critical Systems Deferred Maintenance (CSDM), which are the updates needed for the parks to effectively function.

Colorado ranks 18th in the country in total value of its DM and 11th in CSDM (with more than $40 million, according to the NPS). Below are the numbers released for a few of Colorado’s parks, as well as some ways you can help lower the totals. Time to get our hands dirty.

Rocky Mountain National Park

DM: $62,761,290

CSDM: $25,666,501

Get Involved: Volunteer individually or in a group.

Mesa Verde National Park

DM: $56,939,227

CSDM: $10,837,547

Get Involved: Volunteers can sign up for a one-time event or on a recurring basis.

Colorado National Monument

DM: $20,474,622

CSDM: $1,440,806

Get Involved: Volunteer opportunities are listed from April to October.

Curecanti National Recreation Area

DM: $10,387,384

CSDM: $1,497,299

Get Involved: Contact the park and ask for the volunteer office; they will create an opportunity for anyone interested.

Great Sand Dunes National Monument and Preserve

DM: $8,032,789

CSDM: $1,651,474

Get Involved: Opportunities range from computer database management to trail maintenance.

(Read 5280‘s guide to planning a trip to the Great Sand Dunes.)

Black Canyon of the Gunnison National Park

DM: $6,514,686

CSDM: $533,348

Get Involved: Black Canyon will list specific volunteer opportunities as they become available throughout the summer.

—Photo credits (from top): Amy Thomson (2), Shepard4711 / Flickr via Creative Commons, Amy Thomson (2), daveynin / Flickr via Creative Commons