Sediment and sediment-water samples were collected within the Rio Grande channel and its delta upstream of Elephant Butte Reservoir during four field campaigns spanning between July 2021 and September 2022: (1) July 4-6, 2021, (2) March 20-22, 2022, (3) May 6-8, 2022, and (4) September 16-18, 2022. Sediment analyses were conducted on four sample types: (1) suspended sediment, collected from water in the Rio Grande channel at two-thirds of the total channel depth below the water surface, (2) bed material, from the Rio Grande channel, (3) shallow stratigraphic column samples, collected from 0 to 0.5 meters in depth in the Rio Grande Delta, and (4) Elephant Butte Reservoir water samples, collected near the mouth of the Rio Grande at the top (0.5 m below the water surface) and bottom (0.5 m above the bed) of the water column. The sediment analyses reported herein include computing Suspended Sediment Concentration (SSC) for sample types 1 and 4, and Organic Matter Content (%) for all sample types (1-4). SSC was determined by measuring the water volume of the sample, then freeze-drying and weighing the mass of sediment to obtain a concentration (kg/m^3). OM% was determined by performing Loss on Ignition (LOI) on all sample types (1-4), which removes organic material from the sample through exposure to high temperatures in a muffle furnace. The purpose of these analyses was to characterize the amount and type of sediment transported and deposited within Elephant Butte Reservoir and its delta during different times of the year.

1. Bed material, mostly from the Rio Grande bed, and a few from mid-channel bars and/or just off the river mouth.2. Suspended sediment, all from the Rio Grande during active flow. Samples were collected at 2/3 of the total depth in the river water column. 3. Reservoir water, collected downstream from the mouth of the Rio Grande. "Top" in the location name means the sample was collected 0.5 m below the water surface, and "Bottom" means the sample was collected 0.5 m above the bed.4. Stratigraphic column, which were samples collected from shallow stratigrahpic pits in the deltaic floodplain, and the banks of the Rio Grande.