This name, however, has also been applied to wide tracts of lowland which embrace portions of several valleys, but are defined by lines of heights on each side; the best example is afforded by Strathmore - the " Great Strath " - between the southern margin of the Highlands and the line of the Sidlaw Hills.
A glen is a narrower and steeper-sided valley than a strath, though the names have not always been applied with discrimination.
Now, Strath Brora was cleared in 1819 or before then for the upper part under the great Marshall and Atkinson sheep farm.
Later came the alluvial silting-up. Slowly, but surely, the deltas of the tributary streams advanced into the lake, floods deposited their burdens of detritus in the deeper places, the lake shallowed and shrank and in its turn yielded to the winding river of an alluvial strath, covered with peat, reeds and alders, and still liable to floods.