Darien has been the scene of a great deal of surveying and exploration from the time that Columbus, in 1503, coasted along its shores, hoping to find a strait connecting the two oceans, up to the present time. Balboa, in 1510, discovered the Pacific by crossing the Darien mountains from Caledonia Bay. This discovery taken in connection with the broad indentations of the land noted by Columbus, led the old world to believe in the existence of a strait, and the entire coast on each side of the new world was diligently searched. The Cabots, Ponce de Leon and Cortez interested themselves in this search and it was not until about 1532 that all expectations of finding the strait were abandoned. The idea of a direct natural communication between the oceans being thus dispelled, the question of an artificial junction arose, and in 1551 a Spanish historian recommended to Philip II. of Spain the desirability of an attempt to join the oceans by identically the same routes to which the attention of the whole civilized portion of the world is now being drawn, that is, Tehauntepec, Nicaragua and Panama. From this time up to the commencement of the work of the Isthmian expeditions sent out by the United States, and which lasted from 1870 to 1875, but little geographical knowledge relative to Darien was obtained. The United States expeditions undoubtedly did a great amount of valuable exploration and surveying, and while the names of Strain, Truxton, Selfridge and Lull will always be held in high esteem for what they accomplished in this direction, still it is to be regretted that with all the resources at their command they did not make a complete map of the country. And just here I want to bring forward the suggestion that all that has been accomplished and more, could have been accomplished if the various explorers had known, or practically utilized, a fact that my own experience and that of other topographers, in this country and Darien, has impressed upon me; and that is, that it is easier in a rough and mountainous country to travel on the ridge than in the valley. In Darien they were looking for a low pass in the Cordillera and this was what should have first been sought, directly. Having found the low passes the valleys of the streams draining therefrom could have then been examined, and thus all necessary information could have been obtained and the subject exhausted. The plan followed by the Isthmian expeditions was to ascend a stream with the hope of finding a suitable pass. The pass might be found or it might not, and if not, so much labor as far as the direct solution of the problem was concerned was lost. A pass of low altitude was of primary importance and should have been sought for in an exhaustive way.