Tom Slade at Bear Mountain by Percy Keese Fitzhugh

Tom looked in the cabin but, as he had suspected, the coil of rope had not been brought from the car. So he set forth through the woods to their obscure parking place.

Meanwhile, Brent proceeded with a systematic exploration of the old well. Directing his flashlight at the crevices in the masonry of the shaft, he scrutinized and removed every removable scrap of stone which might have concealed something. This inspection he carried as high as his arms could reach. He searched, not only for a metal box, but also for any remnants of a smaller and perishable container. Here and there where a stone in the wall looked as if it might easily be dislodged, he worked it out and scrutinized the hollow place it left. He proceeded upon the supposition that, if the money were there at all, it would be secreted in the wall somewhere. It was there, of course, that in all likelihood no absolutely complete search had ever been made.