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Allen Telescope Array at the Hat Creek Radio Observatory

Visitor or Interpretive Center
Allen Telescope Array at Hat Creek Radio Observatory. – Alicia Fitzgerald

ADA Accessibility Notes

The site is generally level and is ADA accessible.

The Allen Telescope Array (ATA) is a joint effort by the SETI Institute (Search for Extra Terrestrial Intelligence), located in Mountain View and SRI International, which is located in Menlo Park, CA.

The Allen Telescope Array (ATA) at Hat Creek Radio Observatory is a 42-dish radio telescope that can operate as a snapshot camera, rapidly surveying large swaths of the sky. It operates over multiple frequency bands concurrently and can operate as a single large dish (by pointing all dishes in the same direction) or as 42 independent dishes (looking in different areas of the sky simultaneously). The array is referred to as a large number of small dishes that together produce data and observations about deep space. This approach of many small dishes is more adaptable, economically efficient, and easily upgradable than one single large dish for gathering data. At full build-out, the Allen Telescope Array is envisioned to have 350 individual dishes.

The high-tech scenery of the advanced satellite dishes makes a striking contrast to the largely rural and forested National Forest Lands of the Hat Creek Ranger District which surround the Observatory. The Allen Telescope Array is the first radio telescope primarily dedicated to SETI research, focused on the skies and observing radio waves from deep space. It can also be used for tracking and “finding wayward” satellites.

The mission of the SETI Institute is to explore, understand, and explain the origin, nature, and prevalence of life in the universe. SRI’s mission is “World-changing solutions making people safer, healthier, and more productive”.

The Hat Creek Radio Observatory is open to visitors 9:00 am – 3:00 pm, Monday – Friday, closed all major holidays. A self-guided tour is available, which consists of four kiosk’s containing information about the ATA, and a short video is available to view in the lobby. You can see the signal processing room through the glass and see the array of 42 telescopes which make up the ATA. Large groups are encouraged to call ahead to make arrangements for a guided tour (subject to availability of tour guide), (530) 335-2364.

Driving directions: From Highway 89 (watch for sign Hat Creek Observatory) turn onto Doty Road Loop, follow along until you see a sign “Hat Creek Radio Observatory”, turn onto Bidwell Road, follow 1.8 miles to the entrance gate (black double gates), turn right into the observatory and continue straight 7/10’s mile to the Main Office.

Pet Friendly Notes

Pets are welcome, owners are asked to clean up after their pets.


9am - 3pm, Monday through Friday.

Seasons Open

Open for tours and visits year round.


No fees, but donations are accepted.

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