JEMEZ SPRINGS — Trustees who oversee the Valles Caldera National Preserve are acknowledging that becoming financially self-sufficient is a challenge to every aspect of managing the former Northern New Mexico cattle ranch.

The trustees said in a report to Congress they may have to request funding for maintenance of existing facilities, to meet requirements of the Americans with Disabilities Act and for possible new facilities to support public programs on the preserve.

"It is our opinion that without adequate infrastructure, the trust will not be able to meet the financial self-sufficient mandate of the (Valles Caldera Preservation) Act," Gary Bratcher, the preserve's executive director, wrote in the report's cover letter.

Purchased by the federal government in 2000 for $101 million, the 89,000-acre former cattle ranch is known for its meadows, streams, forests, volcanic domes and huge elk herds.

The preserve is managed not by a federal agency, but by the trustees. It's an experiment in the way public lands are managed — only the Presidio in San Francisco, a military base-turned-park, has a similar governance.

The Valles Caldera board is charged with protecting the land's natural and cultural resources, providing recreational opportunities, operating it as a working ranch and being financially self-sufficient by 2015.

Bratcher's letter said the trust is committed to the experiment.

"We realize we are faced with many challenges," he wrote. "The Valles Caldera Board of Trustees and the trust staff are prepared to overcome these challenges in a collaborative manner."

The 51-page report released Tuesday shows preserve officials have focused on increasing revenues and public access over the last year.

For the first time, the preserve was open to visitors seven days a week during the summer. Preserve officials said the summer expansion resulted in nearly 25 percent more visits than the previous year.

Recreation revenue increased by 5 percent in 2008 fiscal year to $584,000, while the preserve's grazing program returned more than $58,000 to the trust.

In the report, the trust states public access and use appear to be the key to self-sufficiency, but significant infrastructure investment will be required to take advantage of public interest.

The trust said maintenance, ADA compliance and infrastructure improvements could range from $15 million to $50 million over 10 years. The preserve's operating costs over the last six years have totaled about $3.5 million each year.

Over the next year, the trust said it will look for ways to increase donations, restore the preserve's forested areas and continue planning for long-term public access. The report lists one possibility: a public Christmas-tree harvesting program.