Title.

NCR Mojave Outpost, southwest corner of the map. If you activate the "new sheriff" quest in Primm Beagle gives you a marker for it. She's in the barracks, getting drunk (naturally).

Look for the gigantic statue of two soldiers shaking hands, that's your landmark.

Cass is in the Mojave Outpost at the bar. However, she will not join you until after you have finished a job for the Crimson Caravan near New Vegas. After that, they will send you to negotiate with Cass. Once you've done that, she will join you.

I've been to the place. Thanks! Didn't know she was there, using Arcade currently.

Make sure to dismiss Arcade to the Lucky 38 close to New Vegas before you go get Cass; if you dismiss him at the Mojave Outpost it'll take him forever and a half to hoof it back to Vegas.

Also, I recommend discovering the Crimson Caravan Company map marker (east of Freeside north gate outside the slums, the big rectangular complex) before you leave the Vegas area; that'll make getting her much faster.

Yea I know, I already dismissed him and I'm just running around with ED-E right now. I've already been to Crimson Caravan but haven't done any missions yet.