Lake hazard?

I tried to research this, but can you explain airation hole in frozen lake to me?

An airation hole (if I'm using the correct terminology), is a way for the Park Service, DNR, or other water management professionals to oxygenate the water. They set a steady flow of air through the lake/pond which churns the water and doesn't allow it to freeze properly. I know they do this for fish, stocked or rare, but possibly also for water fauna. I'm curious if they do this for lakes/ponds out here that have G. Trout? acarey, any thoughts?

Airation holes can also occur naturally though. Underwater springs will produce a similar effect (if strong enough), and obviously streams entering lakes make for a horrible crossing point due to this effect. If you see a black spot while skinning on a lake, I would recommend staying far from it, or skirting the shorline. In the deep bc I would imagine that natural occurances would be all you would have to worry about.

I've always been a little leary of lake crossings. Imagine if there was a relatively small avy prone slope that you were uncertain about but could avoid with a little extra effort. 99% of the time you'd likely go the extra mile rather than risk the slope.

I don't think Avalungs work well underwater anyways.

That and with as much volcanic activity as the Cascades have I've always gone around lakes when in doubt.

In Ronin, Sam says, "Whenever there is any doubt, there is no doubt."

Given the geothermal activity in the Cascades, and the thought of going in with skis, poles and a pack.... I tend to go with caution. however, in MT, mid-February, single digit F, no worries.

A couple of stomp and sniff tests are about it for me. As for earthquakes and avys on the lake? Ha ha, so many things to worry about - I try to forget about that climbing as well. There is often open water around streams running into lakes long after they still seem fine to cross (I'm picturing Snow and Dorothy Lakes as I'm writing). If the snow ontop of the ice is getting slushy, or water between the snow and ice I try to at least pick up the pace. Let the heavier guy go first.

Skiers & snowshoers cross Relection Lake in MRNP almost every weekend.  A few inches of ice seems plenty strong.  The problem is that the ice thickness can vary. There are several warm springs around the perimeter of this lake that can make for hazardous ice even in cold spells.  There also seems to be enough current near the outlet to keep the ice thin there most of the winter.  I'm surprised there hasn't been an accident under the trail bridge from campers filling kettles.

New snow can disguise thin spots. Water filling your tracks is definitely a bad sign.

In Ronin, Sam says, "Whenever there is any doubt, there is no doubt."

Given the geothermal activity in the Cascades, and the thought of going in with skis, poles and a pack.... I tend to go with caution. however, in MT, mid-February, single digit F, no worries.

I remember crossing one of the Chain Lakes - the one west of Herman Saddle about 20 years ago on a cold mid-January day. I recall that it had been cold for several weeks. As I moved onto the lake snow depths looked to be three feet over the lake, but near the middle of the lake a pole thrust showed 10cm of marginally frozen surface and black water beneath. It scared the you know what out of me as I gently double poled off the lake surface. I came to the conclusion that geothermal activity may have had something to do with it. Otherwise it just didn't make sense. I know of four five locations near the Baker ski area that melt out even in cold conditions to show bare ground. these are obviously geothermal areas. I've also seen a couple near Snoqualmie Pass and several at Blewett Pass.