114 THE IRRIGA TION A GE. 



stand out as distinctly and as evenly as if a surveyor's line had been 

 run along the face of the ridges. 



The terrace effect has one of its best illustrations along a spur of 

 the Oquirrh range at the south of the lake. When the body of water 

 was a sea in truth, these jutting mountains may have been a long, 

 narrow island. Either that, or else they were entirely submerged. In 

 the latter event the surface has fallen more than 1,000 feet, how much 

 more no standard is left by which to judge. The line of the top ter- 

 race is near enough to the summit of the range to permit the theory 

 that once there was a still higher level, above the crest. 



That the belief is not illogical is shown by a comparison of the 

 appearance of hilly islets in the lake, with the mountains back from 

 the shore line. Frequently an island shows a single terrace, on the 

 line, generally, of the lowest of the markings of the coast range. The 

 level of the second terrace comes above the top of the hill, furnishing 

 proof that the island, at least, was once far under water. 



No imaginary description can give an adequate idea of what must 

 have been the size of the primeval sea. Its area, if scientific estimates 

 be accepted as facts, certainly included Bear Lake at the north and 

 Utah Lake at the south. To the east the Wahsatch Mountains and 

 their right-angled spur, the Uintah range, interposed an impassable 

 barrier, but to the west it may have spread over the entire territory 

 of the present Great American Desert. 



Many geographers have asserted that originally it filled the en- 

 tire great basin of which the desert is but a part. Southward, wind- 

 ing its way between the Oquirrh and the Wahsatch ranges, it could 

 have stretched away until its waters lapped the sides of Mount Nebo, 

 whose snow-white head is visible from the shore of the lake, although 

 its foothills are a day's journey away. It is well within the range of 

 possibility that the sacred tiled mountain itself may have been an 

 island in the bosom of the sea. Some persons even have dared to say 

 that Mount Baldy, away to the southwest, was once part of a coast 

 range. More probability attaches to the statement that Lake Sevier 

 is another remnant of the great sea. If the body did extend this far 

 to the south it has left no evidences on the mountains, which, how- 

 ever, are of a formation less apt to be moulded by the water than 

 those farther to the north. 



The greatest mystery about the tideless ocean lurks in the man- 

 ner in which it subsided. By the mountain markings it would seem 

 that some unknown agency made its force felt at regular intervals, 

 turning out a portion of the contents of the basin with the precision 

 of a man emptying a bucket. The power never was exerted in its en- 

 tire force, else there would be not so much as a strip of water remain- 

 ing. If it was of volcanic origin, its application in all probability was 

 made on the region to the northward and northwestward of the shore, 

 each disturbance opening a wider and a deeper way to the sea 



