Efforts are under way in Congress to expand Saguaro National Park by nearly 1,000 acres. It's not a new proposal, but one carried over from the past Congress that seemed little interested in the initiative.

At first blush, the legislation, H.R. 715, might seem on the minor side. After all, is 975 acres really that big of a deal? To answer that question, you need to consider a number of things.

First, this acreage would help preserve wildlife habitat as well as open-space and riparian habitat. In today's setting of urban sprawl and ever-growing populations, as well as the pressures of climate change, every little bit of acreage helps in terms of not just the National Park System but also (and more importantly) in terms of managing the health and vigor of the nation's landscape and wildlife.

That's not to say that entire landscapes across the country should be turned over to the parks. Rather, that concerted efforts need to be made to take a look at available lands adjacent to parks and determine whether it makes sense to protect them.

And that's where the second, perhaps more important, part of the Saguaro National Park Boundary Expansion and Study Act of 2009, which was introduced by U.S. Representative Raul Grijalava, D-Ariz., comes into play. Along with calling for the park to grow by 975 acres -- roughly 300 acres on the west side of Saguaro in the Tuscon Mountain District, and 674 acres on the east side, in the Rincon District -- the legislation would authorize a study to consider whether other areas in the Tuscon Basin might be worthwhile additions to the park in the name of habitat and open space preservation.

“The proposed expansion areas include a variety of unique ecological, geological, hydrological, scenic, historical, and wildlife components, enhanced by the serenity and rural character of the area,” Kevin Dahl, the National Parks Conservation Association's Arizona program manager told the House Subcommittee on National Parks, Forests and Public Lands.

Mr. Dahl, who also spoke on behalf of the Rincon Institute, the Sonoran Institute, and the Tucson Mountains Association, also noted the recreational benefits provided by expanding the park, including the expansion of popular trails; the preservation of important habitat and corridors for native wildlife; and the protection of the park’s scenic views—all of which is now threatened by Tucson’s rapid development and urban sprawl.

“With the Tucson area growing dramatically, and new developments threatening open natural areas, H.R. 715 is critical to preserving this ecologically-rich park,” he added.

This expansion is fully supported by those who own the lands in question.

"All landowners included in this expansion package are supportive of the effort and are willing to be included within park boundaries," said Mr. Dahl. "One landowner is a world-traveling professional photographer who has managed his property as a wildlife sanctuary hoping that someday it would be included in the park.

"Another, whose property was the last to be added to this list, is a native Arizonan who has always known that the piece of land he owns has outstanding natural resource values and belongs in the park."

While Rep. Grijalava is carrying the measure in the House, so far no one in the Senate has taken it up.