The Railcar Flight Trouser is a great alternative to jeans.  A bit less casual then jeans but more rugged than khakis - kind of perfect.  Made of a tough American duck canvas, American hardware, American labels, American thread, and made in Railcar's California workshop.  These pants overtime will offer up a great fade.  A shop favorite.

Slim tapered fit with enough room to move comfortably.  Take normal size for a more slim fit or move up one size for a slightly roomier fit.