Happy Trails Expedition

Happy Trails Expedition is the intro quest to the Fallout: New Vegas add-on, Honest Hearts.

Quick walkthrough

 * 1) Find Jed Masterson with the "Happy Trails Expedition Broadcast" from your Pip-Boy and begin your journey to Zion Canyon.
 * 2) Let Jed Masterson know you're ready to leave once you're traveling alone and carrying 75 (or 100) pounds or less.

Detailed walkthrough
After installing the add-on, you will receive a radio signal from Jed Masterson about the "Happy Trails Caravan" heading through Zion on the way to New Canaan. After that, make your way to the Northern Passage just north of New Vegas and talk to Jed about joining the caravan.

Jed Masterson will only allow you to travel if you're traveling without companions and carrying 75 pounds or less.

Note: You can increase the weight limit to 100 pounds by:
 * Passing various speech checks with Ricky.
 * Passing a Survival check of 50 with Jed Masterson.
 * Having the Strong Back or Pack Rat perks and using appropriate lines in dialogue with Masterson.

The Courier can speak to Ricky at length and call him out on his lies multiple times using the appropriate skill checks (Survival, Guns, Science, etc.), causing him to leave. You will also get the option to keep silent about his lies if he agrees to carry some gear for the Courier (the Courier doesn't actually give him any items, but he/she gets an increased limit).

The Courier may also pass a Medicine check (45) to diagnose Ricky as a Psycho addict, convincing him to leave before his stash runs out on the trail or opening up the ability to sell him the drug and Fixer for the trip at an exorbitant price. This does not prevent the other skill checks from being carried out to convince him to carry some of the Courier's gear or leave the caravan. The player can charge him 30 caps per hit of Psycho up to a maximum of 10 hits, and 1 dose of Fixer for 80 caps (the Courier can't loot his body later and retrieve the items). These prices are by far the most money the Courier can get by selling either one. Motor-Runner only offers 22 per hit for Psycho under the best conditions, while the Courier can get no more than 20 caps with high Barter skill and discounts at a regular vendor.

Additional items can be safely placed in the crate next to Jed.

Once you're alone and carrying less than the weight limit, talk to Jed again to travel to Zion Canyon. Completing this quest will allow you to watch the opening cutscenes for Honest Hearts, and begin the Arrival at Zion quest.