How do I make a footprint polygon of the extent of contour polylines?

[CaseyRoot]

I have some historic contour data of an old river channel that has been digitized and after using Topo-to-Raster, I want to clip only the contoured area out (i.e., the excess interpolated data outside the highest contour). The contours follow the channel and then do not extend into the terrain above so all of that data is not needed (or good, for that matter). The easiest way (in my head) is to generate a one-polygon footprint of the contour polyline data and clip the raster that way, but I can't seem to find any simple way of doing. Any advice is appreciated!

[DanPatterson_Retired]

creating a polygon seems reasonable, even if irregularly shaped.  If you could somehow query the raster to get the bounds (ie an elevation above a certain value) you could simply use that as your bounds by setting your analysis mask or analysis extent prior to doing the final 'clip'.  Setting masks and/or extents within arctoolbox tool environments should be part of your workflow anyway.

[AbdullahAnter]

You can convert your contour line to polygons , then use it to make clip

see this link https://community.esri.com/thread/175668