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Water Quality in the Lamar River near Tower Ranger Station, Wyoming

The Lamar River has high quality water and most of the watershed is managed within federal lands. Suspended sediments and total phosphorus are typically at their annual maxima during high flows. Other analytes (e.g., sulfate, total calcium, and total sodium) are at their annual minima during high flows and increase as the river approaches baseflow. Historically, nitrate + nitrite as nitrogen (NO3 + NO2 as N) and ammonia as nitrogen (NH3 as N) are typically below detection levels.

We sampled the Lamar River for water chemistry and core water quality parameters eight times from April to November in 2021. Core water quality parameters include temperature, specific conductance, dissolved oxygen, pH, and turbidity. Results in 2021 were comparable to previous years; phosphorus was low and non-detectable results predominated for NH3 as N and NO3 + NO2 as N. Analytical results and field measurements from 2021 indicate that water quality standards were met.

Water temperatures in 2021 were highest during summer and coincided with summer baseflows. Surface temperatures exceeded Wyoming Department of Environmental Quality water quality guidance (Wyoming Surface Water Quality Standards, Chapter 1) on maximum water temperature for cold water fisheries (20°C or 68°F) on five days in 2021 (18 July, 19 July, 21 July, 1 August, and 2 August). In 2021, average daily water temperatures were higher and occurred earlier than the previous five-year averages (2016–2020).

Line graph of daily average water temperature from 2016 to 2020 and in 2020. Water temperatures were higher than the previous five-year averages
Summary of average daily water temperatures in the Lamar River near Tower Ranger Station, WY (USGS Gage 06188000).

NPS

Line graphs of water temperature from 2016 through 2020. Water temps went just above the WYDEQ Max allowable in all years except 2017 and multiple times in 2021.
Daily maximum water temperature from 2016 through 2020 in the Lamar River near Tower Ranger Station, WY (USGS Gage 06188000). The horizontal, dotted line represents the Wyoming Department of Environmental Quality maximum allowable temperature.

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2021 Water Quality Lab Results

The following two tables contain water quality lab results for the Lamar River from April through July and August through November, respectively. Download tabular data here for these tables.

Table 1. April through July 2021 monthly water chemistry lab results (in mg/L) for the Lamar River near Tower Ranger Station, WY. All samples were processed at Energy Laboratories in Billings, Montana. Reporting limit (in mg/L) is the threshold value that many analytical labs consider to be the lowest reportable value for an individual analyte; this value may be higher than the maximum detection limit. ND = non-detectable result. Some sampling events included a replicate or blank sample where indicated; blank samples are processed using certified inorganic free deionized water. 
Monthly water quality lab results, April–July at Lamar River near Tower Ranger Station, WY.
Water Chemistry Lab Parameters (Lamar River near Tower Ranger Station, WY)Reporting Limit8-Apr11-May14-Jun27-Jul27-Jul Replicate Sample
Table 2. August through November 2021 monthly water chemistry lab results (in mg/L) for the Lamar River near Tower Ranger Station, WY. All samples were processed at Energy Laboratories in Billings, Montana. Reporting limit (in mg/L) is the threshold value that many analytical labs consider to be the lowest reportable value for an individual analyte; this value may be higher than the maximum detection limit. ND = non-detectable result. Values followed by an “H” are from an analysis that was performed after the holding time for this analyte (e.g., Ortho-Phosphate has a 48-hour holding time) but within 24 hours of the method holding times. Some sampling events included a replicate or blank sample where indicated; blank samples are processed using certified inorganic free deionized water. 
August to November monthly water quality results
Water Chemistry Lab Parameters (Lamar River near Tower Ranger Station, WY)Reporting Limit17-Aug7-Sep3-Nov3-Nov Replicate Sample18-Nov

2021 Water Quality Field Results

Download tabular data here for this table.

Table 3. Monthly water quality field parameter results for the Lamar River near Tower Ranger Station, WY.
Monthly water quality field results for the Lamar River near Tower Ranger Station, WY
Water Quality Field Parameters (Lamar River near Tower Ranger Station, WY)8-Apr11-May14-Jun27-Jul17-Aug7-Sep3-Nov18-Nov

More Data

Data prior to 2021 are available at the Water Quality Portal using YELLWQ01 for the project and YELL_LM000.5M as the site identifier for the Lamar River.

Part of a series of articles titled Water Resources Monitoring in the Lamar River near Tower Ranger Station, Wyoming.

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Last updated: March 21, 2024