I'll admit I know very little about beavers so I will ask another question after I explain the situation.
There is a creek that I have been asked to trap the beaver out of due to them absolutely destroying a stand of Aspen. With 1 1/2 to 2 feet of snow on the ground makes it nigh on most difficult to access the creek however did manage to fight my way through the downed trees, brush and brambles and found where they have built what I surmise is a dam however water is only about a foot and a half deep on the upstream side, however the down stream side is about 8 feet below the top of what I think is the dam, my question is could this dam? also be their lodge? No evidence of any other structures 100 yards either upstream or downstream and creek is heavily lined bot sides with basketball or larger size rocks
There is 1 log across the stream where it appears that they are exiting the water to climb over and then renter the water.
If in any state other than WA would put out a couple 330's and or some # 3 CS, however here we are limited to cage traps.
Did make a break in the dam? and place a double door.
But trying to figure out if it is possible that what I think is the dam is in fact the lodge?

In my experience the dam is not the lodge. I have found bank dens next to a dam, but without knowing your situation I couldn't be sure.

I'd suggest you pm Musty and find out what he has to offer.

I have seen once where a beaver, a sub-adult based on the size of the lodge, actually built a lodge on the downside side of a dam. By the time I remembered to try to get a pic of this oddity, we got a big flood and washed most of the dam away. To this day even the dam is now several feet under water thanks to a bigger dam a half mile or so down the creek.

When you say the water was only a few feet deep on the upper side of the first dam, was that at the corners or the middle of the dam? Most times beaver are damming a small creek only feet wide and when the water backs up and out of the banks, the beaver build wings on the dam to contain this extra water. If you keep going you'd likely find a nasty drop if you dont have a wading stick(which you should always carry when walking in water that has had any beaver activity in its history even a century ago).

The entire creek at the dam? Is only maybe 10 to 12 feet wide and where I made a semi break in the middle the water does not completely cover a 12 in H X 15 in W double door cage trap

Can't imagine it being that shallow at the creek section of the dam unless it's ancient and has been filled in with silt

Got any pics?

I have one area where I have trapped where there is a lodge built right in the dam. But there was also a lodge built about 100 yards up stream from the dam. Like stated above maybe walk the bank looking for a bank den. My guess there are a pair or just one new arrival. They can do a lot of damage quick.