3-way switch loop with thhn

So another question comes up as I plan my run for my 3-way switch in the house to operate a light in my detatched garage. The THHN will have to be in conduit from one end to the other, and will go into metal boxes on each end. I already know that bonding the metal boxes is something my inspector is going to be looking for...

So does that mean that I need to pull a ground conductor with the THHN, so I would probably ideally want to pull 2 black runs, 1 red run and a green run and use the green to pigtail so I can bond the metal junction box on each end and ground the switch?

Now that I talked it through it seems to make complete sense, but I'd appreciate confirmation that I have it right since I'm learning that wirint with individual conductors is a little different than the romex wiring I've mostly dealt with.