It is possible to restrict the plotting region by using `RegionFunction`. However, it is also necessary to construct a concave hull of the data, and use a higher `MaxPlotPoints` when making the contour plot. Using RunnyKine's code from [here](http://mathematica.stackexchange.com/a/88769/9490) to construct the region, dat = Flatten[ Import["https://dl.dropboxusercontent.com/u/659996/odd-data.m"], 1]; reg = alphaShapes2D[DeleteDuplicates@dat[[All, ;; 2]], .33]; RegionPlot[reg] [![enter image description here][1]][1] We can now get the proper contour plot, Show[ ListContourPlot[dat, PlotLegends -> Automatic, PlotRange -> All, RegionFunction -> Function[{x, y, z}, RegionMember[reg, {x, y}]], MaxPlotPoints -> 100], ListPlot@dat[[All, ;; 2]] ] [![enter image description here][2]][2] [1]: https://i.sstatic.net/1i50z.png [2]: https://i.sstatic.net/GO5eo.png