Pristine, beautiful, beachy. Off the beaten path.

These touristy catch-phrases describe Cayo Costa Island to a T.

Its pristine beauty is sustained because Cayo Costa State Park occupies nearly all of the 9-mile-long, nearly 3,000-acre barrier island west of Bokeelia.

And, although almost 90,000 people visit yearly, it’s a drop in the bucket compared to the 839,000 visitors to Gasparilla State Park last year.

It's not surprising. Unlike Gasparilla, Cayo Costa is a bridgeless island, with no paved roads, cars or standard electrical service.

The park’s ferry concession or other private boats bring most people here.

The rub is that, once people arrive at the park dock, they typically board the tram that takes them to the small campground or to the nearest stretch of beach.

“And that’s it,” said Chad Lach, park manager.

But there’s so much more to explore on this island, whose name in Spanish means “key to the coast,” including shade-dappled trails, historic artifacts and lagoons.

Lach recently took photojournalist Ricardo Rolon and me on some of the less-traveled island spots.

There’s no reason you couldn’t have a similar adventure.

To get your feet wet, consider attending “Celebrate Cayo Costa Day,” on Saturday, Nov. 7 — a benefit for Friends of Cayo Costa State Park. For $30 (adults) or $20 (children 12 and under) the group is offering a visit that includes transportation, a grilled hot dog lunch and program of demonstrations and activities.

With fall’s more temperate weather taking hold, exploring more of the island is feasible by foot or bicycle. The park rents bikes; its trails are mainly flat and hard-packed.

Here were some of our discoveries:

Quarantine Trail

The nearly 2-mile-long path starts near the ranger station and winds through trees and brush offering dappled shade. The native landscape includes sabal palms, scrub oak, wax myrtle, seagrape and cocoplum.

Its northern end overlooks Boca Grande Pass and Charlotte Harbor. When the tide is low and the water is clear, you can spy stone footers from a long-gone quarantine dock.

The quarantine station was established on the northern end of Cayo Costa for people coming into port through Boca Grande Pass in the late 1800s.

Crews would “raise a yellow flag,” Lach said, “and a doctor would come to the boat, to check for diseases” such as malaria and yellow fever.

Cemetery Trail

True to its name, there is a small collection of seashell-marked grave sites, including that of Capt. Peter Nelson, just off the trail.

“After life’s fitful fever, he sleeps well,” reads the headstone.

Nelson, a Dane and a seafarer, first earned distinction in Southwest Florida as the founder of Alva, a Lee County community 20 miles east of today’s Fort Myers.

Nelson later settled in Cayo Costa, where he became a schoolteacher and postmaster.

By the early 1900s, about 20 fishing families lived on Cayo Costa, where they established a school, a post office and a grocery store. These included the Santinis and the Colemans.

Among the earliest settlers was Capt. “Pappy" Padilla, who came to the United States from the Canary Islands, off the northwestern coast of Africa.

By the 1880s, Padilla had established a fishing “rancho” or camp on Cayo Costa where he and hired hands caught, smoked, salted and packed fish, mostly for export to Cuba. He and wife Juanita are buried on the island.

All of these pioneers, however, were preceded by members of the now-extinct Calusatribe who occupied the island from about 1000 to the mid-1700s.

Research suggests Calusas were fierce warriors, skilled fishers and clever tool makers, creating the latter from seashells. They also gathered shells into mounds, for which various purposes have been speculated.

Cayo Costa, as many other barrier islands in the region, has shell mounds, but they aren’t marked and aren’t accessible to visitors.

More recent historical artifacts can be found here, though. During the second World War, fighters and bombers out of Tampa used Cayo Costa for target practice.

“You can still find the shell casings,” Lach said. He has one on his desk, found about three years ago.

Wildlife

Boca Grande Pass, viewable from the north end of Cemetery Trail, is a hot spot for late spring and summer viewing and fishing of tarpon, a gamefish that’s inspired big-payout tournaments.

Fish for the dinner table also abound, and include black drum, flounder, grouper, redfish, trout, snook, snapper, sheepshead, trout and triple tail.

Dolphins are spotted “pretty much every day,” said camp store manager Ann Palmer. Sheltered coves on the island’s edge are good places to look for manatees, especially as the weather and water cools.

The island has two lagoons, where big alligators are occasionally seen.

The critter collection also includes gopher tortoises, loggerhead turtles, coyotes, raccoons, armadillos, marsh rabbits and black snakes.

Birders can get an eyeful. Roughly 200 species have been documented including frigatebirds, ospreys, bald eagles, hawks, owls, American oystercatchers, black skimmers, snowy plovers and least terns.

Overnight

Most Cayo Costa visitors come for the day only. Those who stay the night though will experience more of the seclusion.

Dan Trescott, who owns one of only 25 or so private homes on the island, estimates just three of those homes are available for short-term rentals.

That means most overnighters will sleep at the state park.

It has 30 primitive campsites that rent year-round for $22 a night. Twelve rustic one-room cabins that sleep up to six people go for $40 a night. Weekend slots for the cabins fill up quickly, especially as the weather improves. All reservations are made via ReserveAmerica.com.

Both cabins and campsites have an outdoor barbecue grill, a picnic table and a fire ring. Campground restrooms are equipped with outdoor showers.

There are no air conditioners or electrical hookups.

There are ample compensations, however.

“You go out there, and just hear the wind blowing. You get calmer. It’s cheaper than going to the psychiatrist,” Trescott said.

Weekday visitors can find uncommon solitude on a shell-adorned patch of beach.

The night sky can be spectacular, with little artificial light pollution.

“We’re not Disney World,” Lach said. “This is an opportunity to show people what the real Florida is all about.”

If you go

What: Celebrate Cayo Costa

When: 9 a.m. to 4 p.m. Saturday, Nov. 7.

Where: Cayo Costa Island State Park

Who: Friends of Cayo Costa State Park, in partnership with excursion boat concessionaire Captiva Cruises and its subcontractors

What: A roundtrip cruise, a hot dog lunch and activities, including children’s crafts, demonstrations, nature walks and shelling.

Benefits: Cayo Costa State Park

Cost: $30 for adults and $20 for children age 12 and under.

Reservations: Required for this special event package

Call: One of the departure locations. From Captiva Island, 239-472-5300; Pine Island, 239-283-0015; Punta Gorda, 941-639-0969; and Boca Grande, 239-472-5300.

Special event details: at www.friendsofcayocosta.org.

Year-round ferry, park information: CayoCostaFerry.com; floridastateparks.org