Before revision: Bolson, a geographic term , for a desert valley , or depression(geology)| depression, the level of which has been raised by aggradation, usually draining into a playa or salt pan, and entirely surrounded by hills or mountains.
After revision: Bolson, a geographic term , for a desert valley or depressionis the level of which has been raised by aggradation, usually draining into a playa or salt pan, and entirely surrounded by hills or mountains.