Oreo tugged on the leash, jarring the camera as I tried to take footage of the fern-lined trail.

“Oreo, sit,” I commanded for what seemed like the hundredth time that morning, then raised the camera up again.

An unreasonably large mosquito floated in front of my face — whining, looking for an opening. I waved it away. It returned.

“We should get out the repellent,” my sister Jillian said. “This is nuts.”

She was right. If we didn’t do something, we’d be eaten alive before we finished the first trail of the Harpswell Hiking Challenge — a challenge to complete eight coastal trails totaling 10 miles in two days.

I aimed to complete the challenge in one day. Jillian had agreed to joined me for quality sister time. Poor Oreo had no say in the matter.

We soaked our skin, and Oreo’s fur, with “Skeeter Skidaddler,” a Maine-made organic repellent made of essential oils. Smelling like spice cabinets, we moved forward and slowly relaxed as we realized the “skeeters” were still buzzing but not biting.

In the woods of Harpswell, the air was heavy with moisture and heat, and I was starting to wonder if I’d gotten us in over our heads.

The coastal town of Harpswell encompasses small islands and spits of land that stretch out into the ocean like fingers. Though houses have been built along much of the town’s 218 miles of oceanfront, visitors can enjoy coastal environment and stunning views of the ocean from more than 15 properties with walking trails.

A Winterport native, I’d never before visited Harpswell. I simply didn’t have a reason to. So a big part of the challenge would be to actually find the trails we were supposed to hike, preferably without driving into the ocean.

By noon, we finished the 2.3-mile Cliff Trail, pausing once for the insect repellent and once more for a drink of water at the top of the 150-foot cliffs that offer beautiful views of Long Reach and a nameless isle. The tide was out, and the water of Long Reach looked more like mud.

Returning to the registration booth at the town offices, we asked for the sticker that would prove we’d completed our first hike. A silent moment passed between the volunteers and us, and then I knew — the sticker had been on the trail. (We should have read the paper thoroughly.) Instead of making us head back to the top of the cliff, they signed the spot where our sticker would have stuck, and we were off to the next trail.

The sun straight overhead, I did a little math in my head (something I loathe to do). It was noon, and we still had seven trails to find and hike. If each trail took just an hour, we’d be hiking until 7 p.m. I turned to Jillian, who sat in the passenger seat poring over the map.

“If this stops being fun, we stop,” I said. “I can always come back and finish this tomorrow.”

She nodded in agreement, but by the look in her eyes, I could tell she was just as determined as I was to finish in one day. There’s something about the word “challenge” that gets the blood pumping. At least, I know it’s true for Sarnacki blood.

Proper adventures almost always have bumps in the road (or trail), unexpected trials and tribulations.

At the second stop, Long Reach Preserve, a breeze swept in and carried off the stifling air and mosquitoes. But in exchange for such good fortune, I was attacked by ants while trying to speak on camera at the trail head, resulting in some interesting footage of me hopping around hysterically, swatting at my legs.

Ironically, it situation brought me back to one of my earliest memories: I’m standing on a rock wall at my childhood home in Winterport and being attacked by red ants. I stand there, frozen to the spot, screaming. Then Jillian — older by a year and change — runs over, lifts me off the rock wall and brushes away the biting ants. My savior.

Not so this time.

Farther down the 1.2-mile loop trail, she explained that she thought I’d prefer having comical footage than be saved from the ants. Maybe she’s right. I’m pretty gung ho about my job.

Under a stand of tall pines, we sat on the soft forest floor and looked out at Quahog Bay. We’d found the sticker, sealed in a plastic container wrapped in orange tape, and filled our second space on the paper. Six more to go. We half-joked about relaxing there in the sea breeze and shade for the rest of the day, then walked on.

In the car, drive, out of the car, hike — and repeat.

Poor Oreo must have been confused. I tried to make it up to him by filling his collapsible bowl with Fiji water, buying him a bone during our pitstop at Bailey Island General Store and feeding him half my peanut butter and jelly sandwich while sitting by the clam beds at Houghton Graves Park, our fourth stop. But by our fifth trail along the rocky cliffs on Bailey’s Island, he laid down on the sun-warmed rock, his way of saying “enough is enough.”

He couldn’t have picked a more beautiful spot to stop. The coastal trail to Giant’s Stairs was our favorite walk that day. The short trail, less than a half mile, was lined with wild rose bushes and open to the ocean, the sun and the warm breeze. Waves crashed against rocks that resembled giant steps — hence the name — and for one of the few times that day, we lingered and forgot the sinking sun.

After a few deep breaths, we walked back to the car and carried on to Mitchell Field, an old U.S. Navy base where we met another bump in the road as Oreo was approached and nipped at by two large dogs that were not on leashes. We had already ran into several unleashed dogs that day on the trails (all of which display signs that remind owners to keep their dogs on a leash), and by this point, Jillian and I were downright frustrated that so many people ignored the rules.

The shadows were growing long as we reached the eighth and last trail at Skolfield Shores Preserve, where we followed white blazes over bridges and through a beautiful forest to find the last sticker on Merrucoonegan Loop Trail.

After a congratulatory high five, we placed our Harpswell Hiking Challenge sheets — plastered with stickers, proof of hours of hiking — into the mailbox at the Harpswell Town Offices.

A big thanks to my sister, who didn’t complain once, and to Oreo, who slept all the way home.

Aislinn Sarnacki

Aislinn Sarnacki is a Maine outdoors writer and the author of three Maine hiking guidebooks including “Family Friendly Hikes in Maine.” Find her on Twitter and Facebook @1minhikegirl. You can also...