Where are all the park rangers these days?

On a recent visit to Yosemite National Park, I was enchanted by new paved trails and boardwalks that meandered through towering pines, shady glades and rippling streams at the base of Yosemite Falls.

Along the way, I also found new interpretive plaques, one of which alerted me to a small granite spur near the Upper Falls called Lost Arrow.

“Its name comes from a story about a deer hunter who was in the high country celebrating his conquests,” the plaque said. “From the cliffs above the valley, he shot a victory arrow into the air. When the wayward point dropped to the ground, it turned to stone.”

This was just the sort of insight, I mused, that a park ranger might provide – if you could find one.

During my several hours in Yosemite Valley, I never saw a ranger. I had the same experience last summer at Grand Teton National Park in Wyoming.

What has happened to these once-ubiquitous helpers in the funny hats?

The short version of a complicated answer seems to be this: Some are gone, some have been reassigned and some have been replaced by volunteers and employees of nonprofit groups and concessionaires – the private companies that run lodges and other services at parks.

In the last decade, the National Park Service has added 20 parks, an increase of 5.4 percent and totaling more than a million acres, but it has added only 4 percent more employees. (The agency could not provide separate figures on interpretive rangers – those who guide and educate visitors.)

But in the last two decades, officials of several national parks in California told me, the ranks of such rangers have dwindled in many parks. The root reason, they say, is a persistent shortfall of government funding. Because of this, many parks have called on so-called partner organizations to fill in the gap.

One of these, the private, nonprofit Yosemite Fund, based in San Francisco, raised most of the $13.5 million it took to renovate the Yosemite Falls visitor area. Employees and volunteers from another private nonprofit, the Yosemite Association, based in El Portal, Calif., answer phones, help staff the visitor center and conduct seminars. Delaware North, the park’s concessionaire, also runs educational programs.

“If there are four or five programs a night, maybe only one is done by a National Park Service ranger,” said Scott Gediman, a Yosemite spokesman. It’s possible, he said, to spend several days in the park and attend a full schedule of walks and programs without ever encountering a park ranger.

Even the daily van tours of Yosemite Valley are run by Delaware North, albeit with a real ranger on board. The price: $22.50 per adult.

Gediman said Yosemite had maintained services by recruiting private help. At other parks, however, a dearth of interpretive rangers means fewer nature walks and evening programs and shorter visitor center hours.

At Sequoia and Kings Canyon in the southern Sierra Nevada, the naturalist program is “significantly smaller” than it was 20 years ago, said Bill Tweed, chief naturalist for the twin national parks.

In that time, he said, the parks have lost about a quarter of their back-country rangers (a dozen patrol the two parks, which total 865,952 acres), half the staff at wilderness permit stations and more than a third of their naturalists, who now number 25.

“We have reduced programming proportionately,” Tweed said.

In the 1980s, when it was still a national monument instead of a park, Death Valley conducted more than 100 naturalist programs per week in winter, said Terry Baldino, chief of interpretation. Now, it runs about half as many.

“Death Valley would normally have about 110 permanent employees,” he said. “We’re short about 35 positions that we can’t fill because we don’t have the funds to do it.” Five of the unfilled slots are for interpretative staff.

Without more money, Baldino said, he might need to eliminate half the interpretive programs next winter.

It’s tempting to blame the invisibility of park rangers on budget cuts. But naturalist Tweed, who’s been at Sequoia-Kings Canyon for more than 25 years, said the problem is more complicated.

Financially, “This has been the best year for the park service in a number of years,” he said.

After recently losing ground, he said, “We received support from Congress that turned out to be a small net gain, instead of a small net loss. In the longer run, over the last 20 years, the overall pattern has been one of very significant growth in budgets.”

But budgets haven’t kept pace with inflation and increased demands on the parks’ mission, he said.

“It costs enormously more to build a trail today than 50 years ago,” Tweed said. “Then, all you needed was a guy with a rake. Today, we’re building handicapped-accessible trails, with hardened bases and 5 percent grades. We need an engineer, a surveying crew, a contracting officer and more.”

Twenty years ago, he said, about the only medical care available in parks was first aid. Now, many rangers are trained up to paramedic level. Jobs such as air quality specialist, cave manager and aquatics systems manager didn’t exist in the past; now they’re routine, he added.

“Law enforcement is now a much more complex business,” Tweed said. “Twenty years ago, a ranger could write a $20 citation to a visitor without any training.” Now, rangers are trained up to police standards at a federal law-enforcement academy in Georgia.

Competing demands on tight budgets force parks to divert money and ranger staff from interpretive programs to other tasks.

The fact is that private groups are doing jobs once performed by park rangers. The devotion of these citizens who volunteer their time and money is inspiring. But the federal government traditionally has funded the basic operations of these public treasures.

The issue gets renewed attention each year as Congress decides how much money to give the parks. The funding system is complicated, and the debate is predictably bitter and confusing.

But here’s an idea we can all understand: voluntary contributions to the parks on our federal tax returns, in which we could designate a part of our tax refunds to go the National Park Service.

That’s what Reps. Brian Baird, D-Wash., and Mark E. Souder, R-Ind., are proposing in their National Park Centennial Act, introduced in March. A companion bill was introduced in the Senate in April.

I’m not sure this is the perfect answer, but I give these two high marks for creativity and for the bipartisan endeavor. If their bill passes, I just might check off the parks box on future tax returns.