LAKE MINCHUMINA, Alaska — Freezeup arrived with a bump here, when temperatures dropped the last few critical degrees just a couple days after a major October rain storm. The subsequent river flooding only augmented the high water we had all summer and fall. Before all that extra water could run off, it froze, affecting our world for better and for worse for the rest of the winter.
High water makes most frozen creek crossings easier. Some creeks usually have steep, three-foot-high banks that we crash down and scramble up. This winter ice levels lie just a foot below the surroundings, making the crossing startlingly smooth.
Flood plains along the river lie encased in shell ice after a rain-driven flash flood rushed through, partially froze, and then drained away. The remaining thin crust of ice, suspended by grass above six or eight inches of air, hides the rough ground below.
As soon as conditions seemed safe, I ran the snowmachine out the first two miles of trail to pack the marsh grass so falling snow could cover the flattened surface, reducing drag on the dogsled. As I traveled, my machine dropped repeated through the shell ice onto the drained surface below. Heading out later with the dog team to extend the broken trail, I spotted a place where my machine had actually dropped through shell ice into a knee-deep puddle of swampy water.
Insulated from cold air by the layer of ice over air, the water hadn’t frozen yet and my dogs had to wade through it. Luckily, with the puddle only a few feet across, the speed of the machine had carried it over and I’d never realized it was there.
With old Clarence boldly running in loose lead ahead of the team, my dogs pushed over hundred-yard stretches of shell ice, each paw breaking a hole through the quarter-inch ice before dropping another eight inches or so to the ground below. Here and there, in low-lying areas or shallow channels in the marshes, they hit unfrozen water lurking beneath the shell ice.
Levels of frozen lakes and rivers fall as excess water drains away, leaving shorefast ice high and dry. This often creates wide cracks where slumping beach ice joins ice floating on water. Small cracks pose no problem, but when they widen to three or four inches and are a foot deep, they can trip up or injure dogs, people, and even sleds.
Sometimes when ice sages with lowering water, the shorefast ice clinging to river banks forms a shelf with hollow air beneath that insulates the water below, preventing it from freezing. That’s where we go to cut a water hole or check the water depth. Instead of chopping through a couple feet of ice, we might hit air with a single blow, revealing the water underneath.
That’s also a likely spot to crash through by accident and is especially dangerous when it occurs over swift, deep water, so I’ll be a lot more cautious checking crossings when I head out the long trapline trail. Some creeks will even have a shell of thin ice spanning the entire surface and suspended over open water.
The late flood probably sent the few snowshoe hares we still have around fleeing for higher ground. Returning, they’ve found their world elevated a foot by the shell ice, giving them access to a whole new feed level of willows that were too high before.
Smaller critters — voles, shrews and the like — probably faced a chaotic world as their homes and feed supplies disappeared underwater. Most were probably unable to travel far enough to avoid the water, so the low-lying marshes close to the river may be short on these little beings, so critical to the food supply of fox, weasel and other smaller predators.
Our horses too don’t appreciate stepping through ice that crashes loudly beneath their hooves. They wisely stay away from such a tenuous surface and the uncertainty of what might lie beneath. Unfortunately, that has walled them off from a half-mile stretch of some of their favorite winter marsh grass.
Even though our firewood is all under cover, the wet summer and late rain didn’t help it, either. The high humidity penetrates through dry wood, reducing the BTUs we should be getting from split birch carefully seasoned for two summers.
Our under-ice gill nets usually fill much more quickly when water levels stay high, and our efforts this year have been well-rewarded. But when we set one net on the west side of the lake, instead of finding the beautiful clear winter water we expected, Julie and I found the murky red-brown water characteristic of a vegetation-laden swamp. Whether this had anything to do with the late-season rain is only speculation.
As we push farther out the long trapline trail, we may find other anomalies. Did that big October rain fall as snow at higher elevations? Did other rivers cause extensive shell ice as well? How dangerous will the creeks be? For the rest of the winter, we’ll be experiencing the results of freezeup conditions — for better or for worse
Trappers and life-long Bush residents Miki and Julie Collins have written three books, which are available at Gulliver’s Books in Fairbanks. They live in Lake Minchumina.