13th.--We had a day of disagreeable and cold rain and, late in the afternoon, began to approach the rapids of the cascades. There is here a high timbered island on the left shore, below which, in descending, I had remarked, in a bluff of the river, the extremities of trunks of trees, appearing to be imbedded in the rock. Landing here this afternoon, I found, in the lower part of the escarpment, a stratum of coal and forest-trees, imbedded between strata of altered clay, containing the remains of vegetables, the leaves of which indicate that the plants wore dicotyledonous. Among these, the stems of some of the ferns are not mineralized, but merely charred, retaining still their vegetable structure and substance; and in this condition a portion of the trees remain. The indurated appearance and compactness of the strata, as well, perhaps, as the mineralized condition of the coal, are probably due to igneous action. Some portions of the coal precisely resemble in aspect the canal coal of England, and, with the accompanying fossils, have been referred to the tertiary formation.
These strata appear to rest upon a mass of agglomerated rock, being but a few feet above the water of the river; and over them is the escarpment of perhaps 80 feet, rising gradually in the rear towards the mountains. The wet and cold evening, and near approach of night, prevented me from making any other than a slight examination.
The current was now very swift, and we were obliged to _cordelle_ the boat along the left shore, where the bank was covered with large masses of rocks. Night overtook us at the upper end of the island, a short distance below the cascades, and we halted on the open point. In the mean time, the lighter canoes, paddled altogether by Indians, had passed ahead, and were out of sight. With them was the lodge, which was the only shelter we had, with most of the bedding and provisions. We shouted, and fired guns; but all to no purpose, as it was impossible for them to hear above the roar of the river; and we remained all night without shelter, the rain pouring down all the time. The old voyageurs did not appear to mind it much, but covered themselves up as well as they could, and lay down on the sand-beach, where they remained quiet until morning. The rest of us spent a rather miserable night; and, to add to our discomfort, the incessant rain extinguished our fires; and we were glad when at last daylight appeared, and we again embarked.