How do I get only parts of a raster?

[AnnaSenior]

Hi!
I am looking at different characteristics in watersheds and I want to know how to delete parts of a raster that is outside the polygon boundries I am interested in. For instance if I do an interpolation from points to raster the resulting raster extends outside the edge of my area of interest. How do I delete the "outside" parts? Does anyone know?

The same goes for elevation data I have recieved, it is for a a larger area then I am interested in, how do I exclude what I dont want to be part in my continous work?

/

[DonovanCameron]

You can use the clip tool and there is an option for you to be able to clip it to a polygon (irregular shape).

Or, when running analysis, apply a mask in the environment settings of the tool.

[AnnaSenior]

Thank you! The mask thing worked. i think I will be a common visitor to this forum for a while!