Instead of following the track of Garcia and his companions, by the Tapalquen, after a consultation with some guides, who professed to be well acquainted with the intervening country, General Rodriguez determined upon marching direct across it to the Tandil; an attempt, as it proved, more adventurous than prudent. On the 10th of March the troops left the Guardia del Monte, and had hardly crossed the Salado when they found themselves in the midst of apparently interminable swamps, thickly set with canes and reeds higher than their horses' heads. It was with great difficulty that the waggons and artillery were dragged through; nevertheless they foundered onwards as far as a lake, to which, from the clearness of its waters, they gave the name of Laguna Limpia; but there it became absolutely necessary to halt in order to reconnoitre the country before proceeding further. So far they had been grossly misled by their guides, whose only knowledge of the country it appeared had been acquired in excursions in quest of nutrias, which little animals are found in vast numbers in these swamps; but nutria catching and the march of an army accompanied by heavy waggons and artillery are very different things, and the wonder is that all the guns and baggage were not left behind in the bogs. The marshes themselves are formed by the streams which run into them from the hilly ranges further south, and which seem not to have sufficient power to force their way through the low lands either to the Salado or to the sea-coast. Beginning from the morass in which the Tapalquen joins the Flores, they extend far eastward, and render useless a considerable tract of country south of the Salado.