The term midnight sun refers to the polar phenomenon where the sun doesn't fully set below the horizon on and around the summer solstice. However, "midnight sun" is often informally used when describing the long daylight hours and twilit nights experienced by areas of Alaska where true midnight sun does not actually occur, which includes most of Alaska's population centers and major tourist destinations. That's why I prefer the less ambiguous term polar day when referring to the 24/7 daylight experienced by the Arctic.
Hiking only during traditional waking hours is a sad waste of polar day. This goes double for photographers since the light is better when the sun is flirting with the horizon. So, on an excursion above the Arctic Circle following the recent summer solstice, I decided to go for a day hike in Alaska's Brooks Range at 'night'. I started my hike shortly before 9 p.m., ascending through a valley immediately west of the Dalton Highway just south of Atigun Pass. A clear-running creek flowed through the valley, fed by dozens of smaller streams cascading down the surrounding mountains.
I had traveled only a short distance when I saw footprints in the creek bed. They appeared to be less than a day old and left by a single person. Without the footprints, it would have been tough to tell anyone had ever been there: there was no social trail, no litter, no cairns, and no fire pits—not that there was any wood to burn in the treeless tundra.
After a few miles of easy hiking, I reached the base of a pass. At that moment, the clouds lowered over the mountain peaks around me and steady rain began falling. I tightened the hood of my rain jacket and began ascending the steep scree slope. After the slope lessened, the rain trailed off and the sky began to clear. The peaks of the mountains reemerged from the clouds with a dusting of fresh snow. The clock had struck midnight already and the clouds were beginning to glow with sunset hues, while the sun itself had disappeared behind the mountain on my right.
On top of the pass, I encountered a matching pair of shed caribou antlers. I passed several more sheds conspicuously laying on the open tundra during my trek. Despite all the sheds, I failed to spot any caribou. In fact, rather surprisingly, birds were the only wildlife I encountered.
A creek flowed down the other side of the pass, but it dropped over a small waterfall into a short ravine lined by cliffs, so I was forced to cross several snow slopes where I sunk to my thighs in snow before I was able to gain the rocky creek bed. I found part of a Dall sheep jaw next to the creek, along with Dall sheep tracks and wolf tracks. I also found the tracks of the mystery hiker again.
I crossed the creek before it flowed into the west fork of the Atigun River, then started following the river valley as it gently curved northeast back to the highway. The classic U-shape of the valley indicated a massive glacier once flowed through it, but there was no glacier left to be seen. The true midnight sun peeked through a thin gap in the clouds, painting the mountains behind me with shifting patches of alpenglow. As I approached the edge of the river, I was astounded by the vivid blue color of the lingering aufeis—sheet-like ice formations partially covering the river formed by the repeated flowing and freezing of groundwater during the winter. A caribou antler laying near a 7-foot thick slab of ice begged for a photograph.
As I plodded along the tundra, I began seeing heavy signs of bear: a few bear tracks along vague game trails, ubiquitous scat (they had been eating plenty of grass), and a clump of golden-brown fur. I kept my eyes open for bears and other wildlife, but the animals had seemingly vanished, perhaps into the countless side valleys I passed. Each side valley was worthy of its own day hike, with many of them containing roaring waterfalls and easy ridges leading to higher elevations. I kept hoping for the clouds to part, but the best I got was a few glimpses of 3 a.m. blue sky.
Later, as I steadily approached a bend in the valley, I saw a curious display. A bright beam of sunshine would light up part of the tundra like a golden spotlight for a few minutes, then the light would disappear for a few minutes until another ray burst through the clouds. It continued cycling like this for over an hour, almost like a light switch was being thrown on and off. Eventually, the switch turned off for good and the light on the rest of my hike was rather unspectacular.
As I crested a small rise where the valley finally curved toward the highway, I spotted an orange tent gleaming in the sun about a mile away. It was the mystery hiker. I didn't disturb whoever it was, but I wonder if they saw my footprints later in the day and puzzled over them like I did theirs.
I started to run out of gas with a few miles to go. With the pipeline in sight and the weather slowly trending toward rain, I forced myself to keep going, rather than pitch the tent I had brought in case I encountered foul weather. I arrived at the Atigun River shortly before noon, too tired to bother finding a spot where I might cross without getting my feet wet. Unlike many of the rivers I've crossed in Alaska, I could see beyond its surface and didn't have to guess if the water would stop at my shins or above my waist. I crossed two channels that were both top-of-the-knee deep, then trudged in wet boots the final span to the highway, ending about 19 miles from the start of my route and 13 highway miles from my car on the other side of Atigun Pass.
I planned to hitchhike back to my car, or else start walking back with my thumb extended if no one picked me up after several hours. The first vehicle I saw heading south passed me by. I waited another half-hour for the next vehicle, a semi-truck that stopped to pick me up. The driver told me along the way that he always wanted to check out the valley I had just hiked through, and that he had been seeing a large number of grizzlies above the pass this year. He dropped me off at my car and I drove until I found a quiet road pullout, where I slept until midnight.
Although Alaska's summer tourism season is just beginning to reach full swing around the summer solstice, the solstice also marks the beginning of decreasing daylight hours south of the Arctic Circle, a reminder to residents that another long, dark, brutally cold winter is on its way. It's comforting knowing that polar day will last another few weeks in the Brooks Range and that, if I feel the need to get my lost daylight back, I can just drive north.