There's interesting variations here - at first glance a single big weight is the same as many small ones, but you have to think of the engineering challenges of

There's interesting variations here - at first glance a single big weight is the same as many small ones, but you have to think of the engineering challenges of cabling and motors for a 1 kilotonne mass. So you could use many smaller objects in a stack and move them one at a time, but then you've got the problem of decoupling/recoupling the cable and reaching through the ones that are at the top while lowering/raising the ones at the bottom. Now, the next obvious consideration is using mountains instead of a pit. The rockies are full of 4000M peaks. But a mountain means suddenly we have so many new considerations - mountains aren't exactly a constant slope from peak to foot. But extreme loads on rails are a solved problem - the world's heaviest single fully-loaded rail-car was about a kilotonne (a special schnabel car carrying a reactor up to the Alberta tar-sands). Of course, then you've got a new construction problem - building a train-track that's a near-straight-line up a mountain and can support incredibly heavy trucks. It's probably not workable because of the energy-density concerns, but it sure is neat.