In the month of March, 1857, Mr. Surveyor F.T. Gregory, while engaged on the survey of the lower part of the Murchison, observed that the river came down in flood, though there had been no rain for several months near the coast, and taking advantage of such a favourable opportunity of extending the exploration of the country beyond the point at which previous explorers had been driven back for want of water and grass, he proceeded up the Murchison, accompanied by his assistant, Mr. S. Trigg, following the course of the river for 180 miles. For the last fifty miles the condition of the vegetation showed that there had been heavy rains which had caused the floods in the lower part of the river. The following is an abstract of Mr. Gregory's report to the Surveyor-General, as published at the time in the Perth Gazette:-- We last week intimated that an exploratory trip had lately been made into the interior eastward of the Geraldine Mine. We have now the pleasure and satisfaction of laying before our readers some details of one of the most unassuming explorations, yet important in its results, which has ever been undertaken in this colony. In the latter end of March last, Mr. Assistant Surveyor F. Gregory and Mr. S. Trigg started from the Geraldine Mine with two horses and sixteen pounds of flour, to trace the Murchison to its source, and returned after thirteen days' absence. Mr. Gregory has made a short report of his journey to the Surveyor-General, from which we have been kindly furnished with the following extract:-- While at the Geraldine Mine I availed myself of the circumstance of the Murchison being in flood to ascend that river and complete the sketch of the unexamined portions, as also to gain any additional information that might facilitate the exploration of the country between this and the Gascoyne River. The fact that the natives describe a considerable tract of grassy country extending northward from the head of the Murchison, plentifully supplied with water, was an additional incentive to ascertain from whence the inundation came. TROPICAL RAINY SEASON. GOOD PASTORAL COUNTRY.