This manœuvre succeeded several times, and annoyed the Indians very much; some of them lost their best horses by it. Then it was that they combined to attack the whites in their camp. This news was brought M‘Kenzie by one of his hired spies, and was confirmed by the fact of an Indian offering to sell a horse for powder and ball only. From various other suspicious circumstances, there remained but little doubt in the minds of the whites but that there was some dark design in agitation. In this critical conjuncture, M‘Kenzie again eluded their grasp by ensconcing himself and his party in an island in the middle of the river. There they remained, in a manner blockaded by the Indians; but not so closely watched but that they appeared every now and then with their long rifles among the Shahaptain horses; so that the Indians grew tired of their predatory excursions, and therefore sent a messenger to M‘Kenzie. A parley ensued between the main land {225} and the island; the result of which was, that the Indians agreed to sell horses to the whites at the usual price—the whites, on their part, to give up their marauding practices. Notwithstanding this formal treaty, the whites did not put implicit faith in their Indian allies, nor deem it prudent to leave the island; but the trade in horses went on briskly, and without interruption, M‘Kenzie getting all his wants supplied. He bought, besides, an extra reserve of eighty horses for contingencies, which he sent off to Spokane; and on the return of his men he left the island, apparently on good terms with the Indians, and reached the Walla Walla, to join his associates, on the 1st of June.