I can read maps but I don't know too much about staking claims. From what I understand, there needs to be a few things to stake and maintain a claim.
The ground needs to be physically staked and tagged at X number of intervals and the corner posts need to be GPS'd and mapped From there it is a matter of registering the claim ($Y fee, and can be done online) and each year or so, the claim license needs to be renewed for ($Z). Every so often there needs to be some activity on the ground such as geo exploring and maintaining stakes (i.e. maintaining the claim).
I believe that each individual claim (CUU has 119 individual claims currently) requires annual maintenance and fees. If the claim owner does not maintain its claim or pay the renewal fees, the claim goes into forefeit and reverts back to the Crown.
Forefeiture seems to happen a lot so maintaining dud claims seems to be prohibitive for little guys like Mr Marko. I would think that these fees and chores are not prohibitive to a big outfit like TCK. CUU might try to economize on how much moose pasture it makes its shareholders hold.
This is mostly my conjecture.
Webgogs might have more info on claims.