I am running the 50 miler and I was wondering if MP3 players are allowed while running?

For safety and liability reasons, the use of ear-worn devices by runners while running is strictly prohibited. Such devices pose a danger to yourself and others. The roads are narrow with blind curves and hills and open to two-way traffic. Runner support vehicles and other forest traffic will be traveling by runners throughout the day. Full awareness of your surroundings throughout the event is essential. Ultra or relay runners seen wearing such devices will be disqualified and required to leave the course.

I'm going to run the ultra. Am I allowed to have a support vehicle?

Yes, each ultra participant may have one support vehicle. However, to help reduce vehicle traffic, ultras may also choose a no-vehicle option which includes a fee discount. Runners not using a vehicle may bring drop bags or use the aid station provisions, or both. Due to traffic and safety considerations, support vehicles must park in the aid station/transition zone areas only, rather than trailing or leading runners along the course. Specific rules for support vehicles are provided in the Race Rules and Regulations.

I am running my first ultra. Are ultra "virgins" prohibited from running?

Runners contemplating their first ultra at the mOUnTaiNBACK are not prohibited from participating but will need to provide verifiable information (dates/times/events) of significant distance running experience, including marathons. First-time ultrarunners may be required to sign an additional waiver prior to the event.

Where are the ultra aid stations located, and what will be provided? 
Ultra aid stations are located at 11 locations along the course (see the 50M / 50k maps). The stations are spaced 2.8 to 5.6 miles apart and designated by "Ultra Feed Zone" signs.  See Food, Drink & First Aid for a list of what will be provided.

For runners using drop bags, bags provided in advance by runners will be delivered to aid stations 1, 3, 5, 7, 9, and 11. Support vehicles can access all of the stations. Support vehicles should not stop along the course except at these station locations. Race officials at each zone will be equipped with long-range radio and in communication with emergency medical teams on the course.

I am planning to run the ultra but am not sure I can finish in under 12 hours. Can I still run the mOUnTaiNBACK?

The mOUnTaiNBACK is not an easy ultra course. This is why ultra participants are required to provide information on successfully completed marathons or ultras, and relay teams of two are required to provide information on successfully completed half-marathons or marathons. For safety reasons, the course start and closing times were designed to utilize the best daylight running hours at this time of year. Those who think they may need longer than 12 hours to complete the course should carefully consider whether they are prepared to tackle the mOUnTaiNBACK. We cannot be responsible for runners who are on the course after the course closing time. Occasionally we have permitted runners to start early. In this situation, you will have full responsibility for your safety and any needed supplies until you reach an open aid station.

I'd like to know if it is allowed to have someone keep me company (not to pace, I plan on being near the back of the pack) for a few miles.

Pacers, buddies, company of any kind are strictly prohibited on the course for safety and liability reasons. Runners who want frequent company should plan to have a support vehicle whose occupants they can see AT AID STATIONS/TRANSITION ZONES ONLY. This applies to relay runners as well.