No one really enjoys boxing up books, but recently I found myself doing just that, happily, in a small duplex in Denver. I was there to help some friends, who needed to move themselves and their books. You may have helped friends move, but probably not like this, because my friends are the proud caretakers of about 30,000 volumes.

To put it mildly, it was overwhelming. I was surrounded by books, piled floor to ceiling, room after room, enough to fill a small-town library. The task made me a bit queasy, not only because of the work of it, but also because I couldn’t bear the thought of keeping all those tomes sealed away from potential readers.

Fortunately, their storage should only be temporary. This wasn’t a normal move, and this is no normal collection. My friends have been housing most of the set in their duplex and have named it the Rocky Mountain Land Library (RMLL), a vast, one-of-a-kind anthology of books about nature that’s been painstakingly compiled and curated by Denverite spouses Jeff Lee and Ann Martin over the past three decades. Their long-term plan is to set up a residential library in the mountains of Colorado—the nonprofit RMLL already hosts educational programs and visits schools—and in the near term they want to establish a kid-focused nature library in inner-city Denver. But mainly, Jeff and Ann are about real books, made of real paper, to be held by real readers who are eager to learn about nature.

Although the work was exhausting, I kept reminding myself that it was for a good cause. The intersection of books and land is not a dry encounter with nature; instead it’s a wildly exciting journey through both imagination and the real world. I got lost looking at all the titles; the RMLL has books on bears, beekeeping, geography, flora, ecology, conservation, astronomy, geology, archaeology, paleontology, literature, poetry, and Western history. Some were old, some new; some fiction, others nonfiction. All had been collected and diligently catalogued.

While I worked, I reflected on the dreamy quality of my task. At a time when the future of the (literally) printed word might be genuinely endangered, this husband and wife—who, naturally, work at the Tattered Cover; Ann in the marketing department and Jeff as a buyer of bargain books—have been striving to preserve a slice of literature in a way that’s about as old-school as it gets. Let the unsentimental modernist types wonder why they aren’t just digitizing the whole collection; real books and real nature are what the RMLL is all about. “We are all trying to carve out a space where we can slow down and connect with the different rhythms offered by books and by the land,” Jeff says. “It’s incredibly simple, but that’s what the Rocky Mountain Land Library is aiming to do.”

I first became interested in the RMLL years ago when I realized my friends shared three of my greatest loves—books, nature, and books about nature. Like me, they seem to feel the gravitational pull of nature stories; unlike me, they’ve taken their love of books and nature a few steps further by single-handedly creating a library whose worth is estimated to be up to $400,000. Its true value, of course, is impossible to imagine.

The project started simply and small enough, as commitments often do, with a few books on nature bought here and there and stacked on a shelf. In talking to Jeff, I get the clear impression that the books get more room (and consideration) in the Martin-Lee household than either of its human inhabitants do. It may be that the couple spends more on books than other items—such as, say, food.

Collecting the books is probably the easiest part of the endeavor. The trickier issue is what to do with all of them. All along, they’ve been intended for a publicly accessible place somewhere in Colorado, a residential library that would display the books and provide housing quarters nearby, so truly devoted nature readers could stay for days or weeks at a time and seriously study the collection. Lee and Martin are hoping to soon sign a 90-plus-year lease for a residential land-study center in South Park, about two hours from Denver. The idea is to house the books there and offer workshops, conferences, fieldwork, and other activities. “Basically, we wanted a site remote enough to provide the quiet conducive to work and study, so we looked in rural Colorado,” Jeff says. “But we also want to be a vital resource for the surrounding communities, and so we want to be accessible. The RMLL is committed to serving both the local community and visiting writers, artists, naturalists, researchers, and especially all those lifelong learners out there.”

Although the RMLL site search has taken some time, the deliberate pace has helped Martin and Lee bring other facets to the organization. “We’ve slowly developed several outreach programs”—author talks, classroom visits, and two-week residencies—“all to advance the mission of encouraging a greater awareness of our ties to the land,” Jeff says.

The RMLL has been fueled by the best energies of many volunteers beyond this devoted couple. The Tattered Cover has donated shelves, volunteers crated more than 1,000 boxes of books, and Acme Distribution has offered to transport and warehouse the books free of charge until the RMLL has its site. The next step is to find a home for the kids’ nature library, and after that, for the Urban Homestead Learning Center for inner-city Denver. “We are literally packed up,” Jeff says, “and ready to move on to the Land Library’s next stage.”

In the end, I worked until my arm muscles were sore, then called it quits for the day. I’d had the perfect weekend: a stay at Castle Marne, the cutest bed and breakfast ever; a workshop at Lighthouse Writers, my favorite local writing program; a day at the Tattered Cover, the best bookstore in the universe; and one afternoon of packing up books for a good cause. As I taped shut the last box of my volunteer day, I realized something: Even though the task is something we’re all familiar with, in this particular case, it’s a methodical labor of love, much like exploring and learning about nature itself. That’s what makes this unique set of books—and the noble effort to preserve them—such a treasure.