EXPLORATIONS ACROSS THE GREAT BASIN OF UTAH. 



THE GREEN RIVER BASIN. 



LIMITS AND GENERAL CONFIGURATION AND FEATURES-NO IGNEOUS AND METAMORPHIC AND PROB- 

 ABLY NO PALEOZOIC ROCKS-TERTIARY FORMATIONS: THE FORT BRIDGES 8EWB8-STRATI- 

 GRAPHICAL POSITION-SECTION OF THE STRATA-THEIR ORGANIC REMAINS AND F\ I I'M - 

 THEIR FRESH-WATER CHARACTER AND AGE-THE ROCKS EAST OF GREEN RIVER-THE ESTU- 

 ARY FORMATION ON BEAR RIVER-OTHER TERTIARY DEPOSITS-CRETACEOUS, JURASSIC AND 

 TRIASSIC FokmuimNs: IX THE GREEN RIVER VALLEY-ON SULPHUR CREEK-ANALOGOUS 

 STRATA AT THE Mol'TIl JUDITH RIVER IN NEBRASKA-ON BEAR RIVER AND MUDDY CREEK- 

 AT THE NEEDLES-OX WHITE-CLAY CREEK-OX ECHO CREEK-OX WEBER RIVER AND ITS 

 EAST FORK-JURASSIC FORMATION ON THE SOUTH SIDE OF THE UINTAH MOUNTAINS o\ 

 POTTS-S CREEK AND DUCHESNE FORK-COAL IN SAN PETE VALLEY AND NE\R LITTLI SU/I 

 LAKE-THE RED SALT AND UVFSUM FORMATION OF PROBABLY TRIASSIC AGE-ECONOMICAL 

 GEOLOGY- AGRICULTURE - BUILDING MATERIAL - COAL - PETROLEUM - MINERAL SPRINGS - 

 METALLIC ORES— SALTS. 



Iii this section I have comprised the country from the dividing ridge between the 

 Atlantic and Pacific waters, to the eastern limits of the so-called Great Basin. On our 

 line of exploration, it extends from the South Pass to the geological axis of the Wah- 

 satch range ot mountains, which passes near Weber River, a short distance beyond 

 the hvdrographical axis ot that range. It includes the southeastern extremity of 

 Oregon, and the northeastern portion of Utah. I have called it the Green River 

 Basin, on account of the marked basin-shaped configuration of its surface near our 

 route, with the same recent Tertiary strata at its lowest central point on Green River, 

 winch gradually rise toward both extremities and crown the dividing ridges at the 

 South Pass and in the Wahsatch Mountains. Its eastern portion, from the South Pass 

 to Green River, and even beyond, presents the character of extensive plains, scarcely 

 interrupted by slight rises of the ground, while the western part embraces the eastern 

 portion of the Wahsatch Mountains, the broadest and most diversified mountain-chain 

 which we have passed on our route across the continent. There the lower formations 

 rise to the surface; the streams have cut out deep valleys and even grand roekv 

 eanons, and subterranean forces have manifested themselves in numerous upheavals 

 and great dislocations of the strata, which are frequently tilted at an angle of 90° and 

 disturbed in every direction. 



^ The eastern portion of the district is a barren waste, rendered so by the prevail- 

 ]I1 p :m ' !1;ir ;" ,ls character ot the tormations, the shallowness of the soil in many places, 

 " U ' n " " >n/, ' n stnini ni ]llm ' s h>ne and sandstone extend over considerable distances 

 near the Burn**, and the large quantity of saline efflorescences from the rocks, 

 together with the chmatical features of the country; and it would be nearly impass- 

 able if xt was not for the numerous creeks and rivers which come down from the sur- 

 rounding high mountains, the Wind River Mountains, the Wahsatch Mountains, the 

 Lmtah Mountains, <kc, and which along their banks have seams of meadow-land 

 furnishing subsistence to the animals and relief to the eye tired from the endless dust v* 

 sage-barrens and sand-hills. When we approach, however, the foot of the western 

 mountains, we perceive a great change in the vegetation. There are green vall.vs, 

 diversified with groves of timber, and the mountain-sides and uplands are, besides the 

 wild sage {Artemisia), thickly covered with nutritious fodder-grasses, and partly stud- 



