See 26InchSlicks: Crossing Washington State on the John Wayne Pioneer Trail. 10 longest. Of the longest trails compiled by the Rails to Trails Conservancy, here are the 10 longest that are accessible to bicycles: Cyclists ride along the nearly dry Keechelus lake bed in the fall.
Parent material. Parent material is the underlying geological material (generally bedrock or a superficial or drift deposit) in which soil horizons form.
To a soil scientist (the definition we'll use here), a soil is loose material, including mineral matter and organic matter, that supports plants and differs from the original parent material. (Parent material is the stuff that the soil formed from. 'Parent' is probably the wrong term, but is firmly entrenched.