The bulk sampler was a 30 cm diameter by 60 cm long stainless steel cylinder, with large handles on each side. The sampler was worked into the substrate to a depth of at least 30 cm (1 foot), and the material excavated generated a sample ranging from approximately 30 to 80 kg of sediment. The cylinder center was placed at the permeability standpipe location. The substrate surface usually consisted of a coarse layer of gravel and cobble, which was removed and analyzed separately from the subsurface layer. All sediment samples were dried and sieved to 8 mm with rocker box sieves (hand shaking), then sieved from 5.6 mm to 0.125 mm with a mechanical shaker. Samples with large fractions finer than 8 mm (= most samples) were split with a funnel splitter, and the sub-sample then sieved with the mechanical shaker. A combination of field methods was used for sieving, including air drying/sieving at the tributary site, transporting the samples to a central location within the watershed for air drying/sieving, or transporting the samples home for later air drying/sieving. Air drying samples in the sun usually required four to eight hours. We used full “phi” (...) sieve sizes for coarser substrates: 128, 64, 32, 16, 8, then half phi sizes for fine particle sizes: 5.6, 4, 2.8, 2.0, 1.4, 1.0, 0.85, 0.5, 0.25, and 0.125 mm. This selection of sieves gives high resolution to the distribution of fine particles in each bulk sample.