Do you want it for a reference in SolidWorks, or do you need to be able to edit it or extract curves or surfaces from it?
In STL import options you have 3 choices, Solid Body, Surface Body, or Graphics Body.
SolidWorks is limited to importing about 15,000 triangles or so as a Solid Body, and slightly more as a Surface Body. You can import millions of triangles as a Graphics Body, but in general that is only good as a visual reference, since you cannot snap to it or extract curves or surfaces.
If you have Scan to 3D in your license (SolidWorks Professional), you might be able to convert the triangles into nurbs surfaces.