Related by context. Frequent words. (Click for all words.) 52 middens 50 beaver dams 48 contaminating groundwater 48 Soil erosion 48 river bottoms 47 riparian zones 47 sediment runoff 47 woody vegetation 47 riparian vegetation 47 ant hills 46 voracious eaters 46 grazing pastures 46 fecal material 46 streambeds 46 burrows 45 earthen dams 45 beaver ponds 45 marine reptiles 45 creek bottoms 45 bioaccumulation 45 Sea otters 45 gastropods 45 dense woodland 45 overgrazed 45 amphipods 45 reproduce asexually 44 gravel quarry 44 creekbed 44 great crested newts 44 earthworms 44 erosional 43 burrow 43 gravel pits 43 Mesolithic 43 silt fences 43 intertidal zone 43 beaver dam 43 dense brush 43 spawning beds 43 coulee 43 tules 43 groundwater aquifers 43 ant colonies 43 diked 43 lava tubes 43 muskrats 43 Scientists theorize 43 eelgrass beds 43 voles 43 bioaccumulate 42 tailing ponds 42 soils 42 polluting groundwater 42 microfossils 42 rock outcrop 42 bridge abutments 42 aquatic insects 42 recharge groundwater 42 topsoil 42 saturated soils 42 midden 42 sediment 42 alfalfa fields 42 excavated 42 foraging 42 drainfield 42 gopher holes 42 intermittent streams 42 shoreline erosion 42 forested wetlands 42 headwater streams 42 gopher tortoises 42 slime molds 41 mine shafts 41 redds 41 riverbanks 41 sinkholes 41 settling ponds 41 tall grasses 41 streambed 41 riverbed 41 shallow aquifer 41 silts 41 epiphytes 41 salination 41 waterholes 41 diggers 41 ponds 41 ice jams 41 burrowing owls 41 abiotic 41 nocturnal creatures 41 anthills 41 nesting eagles 41 weeds 41 hydrothermal vent 41 dug mass graves 41 Happisburgh 41 tent caterpillars 41 excavate 41 larval stages