UNITED STATES DEPARTMENT OF THE INTERIOR Harold L. Ickes, Secretary GEOLOGICAL SURVEY W. C. Mendenhall, Director Bulletin 913 TRIANGULATION IN UTAH 1871-1934 J. G. STAACK Chief Topographic Engineer UNITED STATES GOVERNMENT PRINTING OFFICE WASHINGTON: 1940 Tor sale by the Superintendent of Documents, Washington, D. C. Price 20 cents (paper) CONTENTS Page Introduction ______________________________________________________ 1 Scope of report------__-_-_---_----_------------ --__---__ _ 1 Precision __ _ ________________________ _ __________________ _ ___ 1 Instruments used._ _ _ _ _ _ _ _ _ 2 Station marks___- _ _.__ __ __ _ 2 Datum_-_-_-__ __________________________ ______ ______-___.__ 3 Methods of readjustment..._____.-.__..________.___._._...___.__ 4 Form of results__-.________________________ _.___-_____.______ 5 Arrangement__.______________________________ _ ___ _ ________ 6 Descriptions of stations._______________________________________ 6 Azimuths and distances.__ ____-_.._---_--_________ -____ __ __ ^ 7 Maps.__----__-----_-_---__-_--_-___-_-___-__-__-_-_-___.-.__ 7 Personnel_ _ __-----_-_-_---_---------_--__-____-__-_.--_.___ . 7 Projects 9 Uinta Forest Reserve, 1897-98_ 9 Cottonwood and Park City special quadrangles, 1903____ _ 19 Iron Springs special quadrangle, 1905____________________________ 22 Northeastern Utah, 1909.. -_. 26 Eastern Utah, 1910 - . 30 Logan quadrangle, 1913._________-__-__'_--______-___:_____.____ 42 Uintah County, 1913___-__. 48 Eastern Utah, 1914.. ... _ _ .. 55 Northern Utah, 1915 (Hodgeson)_____-___ __-___-_-_-__-_--. _. 58 Northern Utah, 1915 <Urquhart)_. ._ _ _. 59 Tooele County, 19221 __ ___ ___ _ ___ 76 Salt Lake and Utah Counties, 1922 ___ ___ _ 83 Northern Utah, 1923__....__._ . _.__._._..._.___.._._.__... 96 Fort'Douglas Military Reservation, 1925__ __ _-__------__--__- 103 Zion National Park, 1928_. ___...._...._.__._._____......_.. 110 Bryce Canyon National Park, 1929.- - . .- . 117 Fishlake National Forest, 1931---------------------------------- 127 Southern Utah, 1933-34. _____ .___-. __ __ __ __ 133 Duchesne quadrangle, 1934___.--__-_--_ --___ __ __-_______- 135 Southeastern Utah, 1934..............._.._...._......__... 142 Appendix.. , ______________________________ _ ______ __ ____-___ 158 Powell Survey, 1871-78 (in part) 158 Tintic mining region,1896____-__------------------------_----._ 161 Bingham special map, 1899. -__ ____-_--__-_-__--_--.______-_ 162 Park City mines, 1901-2..__.___..............._.........___ 163 Frisco quadrangle, 1904._-_.-___-_-___-__-_-_-_____-________.__ 163 Index 165 m IV CONTENTS ILLUSTRATIONS Page PLATE 1. Standard Geological Survey station marks and bench marks____ 2 FIGURE 1. Index map of Utah showing the location of trrangulation proj­ ects in the State._____--__---_________________________ 8 2. Triangulation for Uinta Forest Reserve, 1897-98.__________ 10 3. Triangulation for Cotton wood and Park City special quadran­ gles, 19p3-_----------------------------.--------_---_- 20 4. Triangulation for Iron Springs special quadrangle, 1905____-_ 23 5. Triangulation in northeastern Utah, 1909._________________ 27 6. Triangulation in eastern Utah, 1910____-_-___-_----_____ 30 7. Triangulation for Logan quadrangle, 1913________________ 42 8. Triangulation in Uintah County, 1913___________________ 50 9. Triangulation in eastern Utah, 1914______________________. 56 10. Triangulation in northern Utah, 1915.____________________ 59 11. Triangulation in Tooele County, 1922_____________--____._ 76 12. Triangulation in Salt Lake and Utah Counties, 1922________ 84 13. Triangulation in northern Utah, 1923_________-_--'-_-_---_ 97 14. Triangulation for Fort Douglas Military Reservation, 1925. _ 104 15. Triangulation for Zion National Park, 1928- ____._-_.______ 110 16. Triangulation for Bryce Canyon National Park, 1929__-_._ 118 17. Triangulation for Fishlake National -Forest, 1931 ___________ 127 18. Triangulation in southern Utah, 1933-34._________________ 133 19. Triangulation for Duchesne quadrangle, 1934.___._______.. 135 20. Triangulation in southeastern Utah, 1934._.______._..______ 143 TRIANGULATION IN UTAH, 1871-1934 J. G. STAACK, Chief Topographic Engineer INTRODUCTION Scope of report. This bulletin contains the results of all triangu- lation done in Utah by the Geological Survey of the United States Department of the Interior before 1936 and includes those previously published,1 the work for which was done before 1915. Precision. In general, the triangulation described in this report conforms to the specifications for third-order work as now defined by the Federal Board of Surveys and Maps. These specifications, in part, are as follows: The designations for the several grades of control adopted by the Board of Surveys and Maps January 1], 1921, were precise, primary, secondary, and ter­ tiary, named in order of decreasing accuracy. Prior to that time the terms pri­ mary, secondary, and tertiary had been used for the three higher grades of control. The nomenclature adopted in 1921 did not find wide acceptance, and therefore the Board in 1925 adopted the terms first ordsr, second order, third order, and fourth order to designate the four grades of control, first order being applied to the most accurate grade. This brings the nomenciature into better accord with general usage, and it is also easily understood without explanation by one not acquainted with the terms. * * * Triangulation of the third order is ordinarily used for the immediate control of topographic and hydrographic surveys. Extensions of third-order triangulation or of third-order traverse from triangulation or traverse of a higher order should be made so as to control the entire area to be surveyed. Triangles of third-order triangulation should close with a maximum error of 10 seconds and an average error seldom exceeding 5 seconds. Closures in length on lines of first-order or second- order triangulation, on lines of third-order triangulation previously adjusted, or on base lines, should not exceed one part in 5,000. Instructions for conducting third-order triangulation surveys that were in force during the execution of the work described in this report are contained in Bulletin 788, entitled "Topographic instructions of the United States Geological Survey." Parts of those instructions are now obsolete. The United States Coast and Geodetic Survey, also, has published a description of the methods employed in triangu- 1 The results previously published are contained in the following publications of the Geological Survey: 18th, 19th, 20th, and 21st Annual Eeports and Bulletins 122, 181, 216, 245, 310, 440, 496, and 644. 1 2 TRIANGULATION IN UTAH, 1871-1934 lation and detailed specifications and instructions for the work.2 Some of the triangulation projects in Utah were conducted with more care than was given the average project, as is shown by the resid­ uals in the original adjustments by least squares, and their results approached the degree of precision that is expected of second-order triangulation. However, as these results have been readjusted, with­ out regard to their higher precision, in conjunction with results that are of average, or third-order precision, it is logical to assume that the average precision of all the results here published is third-order. Instruments used. In the triangulation done before 1928, theodo­ lites of the direction type were used. This type was equipped with a 10-inch circle and two micrometers, each reading to 2-second divisions on a scale or its head. It weighed about 28 pounds without its case, and its tripod weighed about 19 pounds. It was well adapted to mak­ ing azimuth observations and was frequently put to that use in the earlier years of the work, when the projects extended far from first- order bases. Since 1928 the use of repeating instruments has gradu­ ally become common. The type now regarded as the standard is a transit theodolite, with which the angles are measured by the method of repetition. It is equipped with a 7-inch circle and two verniers, each reading to 10 seconds. This instrument weighs about 20 pounds without its case, and its tripod weighs 16 pounds. Station marks. The Geological Survey establishes permanent marks at most of its occupied triangulation stations. (See pi. 1.) These are usually of the same form as those used for permanent marks along lines of leveling and transit traverse, such as bronze or aluminum tab­ lets, iron posts, and copper bolts, but they include also drill holes, marks chiseled on rocks, and natural or constructed objects that can be so described that the exact points whose positions have been com­ puted can be unmistakably identified. The tablets are circular in shape, measure 3% inches in diameter and taper from a thickness of three-eighths of an inch at the center to about a quarter of an inch near the rounded edge. During a short period in the earlier years of the Survey's triangulation the tablets set were made of aluminum. The softness of this metal, however, made them susceptible to damage, so that aluminum as a material for tab­ lets was soon discarded. The earliest tablets were made of bronze, and bronze is the material now specified for standard tablets. Each tab­ let is cast with a 3-inch shank extending from the center of its reverse side, by means of which it is cemented into place, and each bears an inscription on its face. The inscriptions on the tablets already placed differ in many .details, because of changes in design at various times. The face of every tablet, however, is cast with the words "U, 8, ! See Hodgson, C. V., Manual of first-order triangulation: U. S. Coast and Geodetic Survey Special Pub. 120,185 pp., 1926; Manual of second- and third-order triangulation and traverse; U. S. Coast and Geodetic Survey Special Pub. 145, 226 pp., 1929.