Research about Colorado, Idaho, Montana, North Dakota, South Dakota, Utah, Wyoming

USGS2026

Methods for estimating selected streamflow statistics at ungaged sites in Wyoming based on data through water year 2021

The U.S. Geological Survey, in cooperation with the Wyoming Water Development Office, developed regional regression equations based on basin characteristics and streamflow statistics for streamgages through water year 2021 (October 1, 2020, to September 30, 2021). The regression equations allow estimates of mean annual maximum, mean annual, mean seasonal, and mean monthly streamflows; frequency statistics for the 7-day mean low flows with 2-year and 10-year recurrence intervals, 14- and 30-day mean low flows with 5-year recurrence intervals, and 60- and 1-day mean high flow with 2-year and 5-year recurrence intervals, respectively; and the 0.1-, 0.2-, 0.5-, 1-, 2-, 4-, 5-, 10-, 20-, 25-, 30-, 50-, 60-, 70-, 75-, 80-, 90-, 95-, 98-, and 99-percent durations for annual streamflows and 0.1-, 0.5-, 10-, 15-, 20-, 25-, 30-, 40-, 50-, 60-, 70-, 75-, 80-, 85-, 90-, 95-, and 99-percent durations for monthly streamflows for most months for ungaged locations in Wyoming that are largely unaltered by diversions or upstream reservoirs. Regression equations were developed for 243 streamflow statistics. Best-subset selection was used to assess explanatory variables for respective streamflow statistics. Exploratory data analyses determined that, of the 81 basin characteristics evaluated as potential explanatory variables, characteristics such as drainage area and precipitation often produced models with the highest adjusted coefficient of determination and lowest mean squared error, as determined in the best-subset selection. To address heteroskedasticity of model residuals, model variables were regionalized using fixed-effects models; the percentages of the streamgage basins in selected ecoregions were defined as interaction terms, which represent the model slope for specific ecoregions. Most models were determined to be statistically significant for probability values less than or equal to 0.1 for one or more regional explanatory variables. The final regional regression equations defined in this report are available for use in the U.S. Geological Survey’s StreamStats web application at https://streamstats.usgs.gov/ss/ .

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USGS1970

Aspects of oil and gas operations on federal and Indian lands of interest to engineers

It is always enjoyable to attend any meeting of the Society of Petroleum Engineers. I am happy to have this opportunity to speak to you because I believe that petroleum engineers can benefit from a better understanding of the Mineral Leasing Act and the regulations that implement the act insofar as these affect or influence your work. The regulations that implement the leasing act are commonly known as the Oil and Gas Operating Regulations. These regulations are officially described as Part 221 of Title 30 of the Code of Federal Regulations. They are printed in a small green booklet which most printed in a small green booklet which most of you have probably seen at one time or other. The requirements of the operating regulations, as specifically set forth in the booklet, or as determined by policy judgments in our various offices, can affect some aspects of your work. I think it would be appropriate first to discuss the two types of lands, Federal lands and Indian lands, which are subject to the Oil and Gas Operating Regulations. Federal lands generally are classified in two categories, acquired land and public domain lands. Acquired lands are lands to which the Federal Government obtained title by purchase, exchange, condemnation, or private gift. These lands are scattered private gift. These lands are scattered throughout the United States and total about 54 million acres, or about 7.5 percent of the area classified as public percent of the area classified as public lands. The public domain lands are lands to which the United States has held title since their original acquisition. There are public lands in 30 states, but the large bulk of the lands are located in Alaska and the Western States. You may recall from your history courses some of the purchases and treaties by which the United States obtained most of the lands now described as public domain lands. The Louisiana Purchase in 1803 included among the Western States most of Montana, eastern and central Wyoming, northeast Colorado, and the northern part of Texas. This treaty also included a large part of the area now generally referred to as The "Midwest". The annexation of Texas occurred in 1845 and it is somewhat surprising to realize that this included, among other lands, a strip of land through western Colorado and a rectangular shaped piece of land in Wyoming, south of Rawlins piece of land in Wyoming, south of Rawlins The acquisition of the Oregon Territory in 1846 brought into the Union parts of western Wyoming and Montana as well as what is now Idaho, Oregon, and Washington.

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