If the find a missile under multiple silo covers game is to be played - each silo would need to have a big access road, one that goes under the soil in the last several tens of meters or 100 meters before the silo itself is reached. and it would have to feature a huge hole inside, so the missile that's brought in on a truck can be erected while underground.
That's one way to do it. A simpler way would be just having a truck bring in either a self contained missile canister, which may or may not be empty - or if there is no canister- to bring in a dummy missile.
Of course, if that route is taken, just wait until media starts proclaiming there is indeed a real missile in every single one of the silos.
All that being said, I'm still not sold on the idea these are indeed missile silos. The windfarm theory, for example, is just as convincing.