Do I need to book tours months in advance?

No. Unless you are traveling during the extreme peak of February, you can easily book tours 24-48 hours ahead of time once you arrive in San Pedro.

Can I drive myself to the sights?

You can, but many remote areas lack cellular service and signposts. Organized tours are safer and provide necessary context about the geology.

Planning an Atacama Desert tour from San Pedro de Atacama

Fly into Calama (CJC), take a shared shuttle directly to your accommodation in San Pedro de Atacama, and book your excursions in person at least 24 hours in advance. Prioritize tours that require high-altitude acclimatization for the final days of your trip to avoid altitude sickness.

Arrive in Calama. Fly from Santiago (SCL) to Calama (CJC). Do not rent a car at the airport unless you are experienced with desert driving; the 1.5-hour drive to San Pedro is best handled by pre-booked shuttle services like Licancabur or Transvip.
Acclimatize for 48 hours. San Pedro sits at 2,400 meters. Before booking high-altitude tours like El Tatio Geysers (4,300m) or Piedras Rojas (4,000m), spend at least two full days doing low-altitude activities like Valley of the Moon to let your body adjust.
Book tours locally. Walk down Caracoles Street in San Pedro to compare prices between agencies. Booking in person 1-2 days before the tour is cheaper than booking online in advance and allows you to check current weather conditions for the high-altitude sites.
Manage your hydration and electrolytes. The Atacama is one of the driest places on Earth. Carry a 2-liter reusable water bottle and drink electrolyte packets daily to combat headaches and fatigue from the dry, high-altitude air.

Do I need to book tours months in advance?: No. Unless you are traveling during the extreme peak of February, you can easily book tours 24-48 hours ahead of time once you arrive in San Pedro.
Can I drive myself to the sights?: You can, but many remote areas lack cellular service and signposts. Organized tours are safer and provide necessary context about the geology.