H2O (Hidden Hill Observatory) User Agreement

H2O Access
Patron Membership
User Agreement Form
Orientation Lecture and Rules




H2O Access

The Tri-Valley Stargazers Astronomy Club (TVS) leases a hilltop from the owners of a Ranch on Mines Road for astronomical viewing and astrophotography. The site is available every night throughout the year to all dues-paying club members who have entered into this user agreement as well as their escorted guests. The site is on private property. It is not a park. It is a working ranch with livestock, ranchers, etc. It is not open to the public. Uninvited visitors are not allowed.

The Tri-Valley Stargazers usually conduct several "open house" nights at the observatory each year. On these nights, anyone (even non-members) can visit the observatory by meeting in a group in Livermore and being escorted out to the site.

The dates of the open house trips are announced in the TVS newsletter, Prime Focus. We try to schedule the open house trips on Saturday nights, near the last quarter moon so that the moonrise near midnight provides a convenient time to end the open house and we do not interfere with the prime new moon observing time reserved for members' use.

The procedure for members to gain access to the site is:

1. Pay the $20 key deposit to the Treasurer, either in person or by mail to: Tri-Valley Stargazers, P.O. Box 2476, Livermore CA, 94551. You will be sent a copy of this agreement.

2. Receive this agreement, read, sign, and return it to the key master, in person or by mail to: TVS, P.O. Box 2476, Livermore CA, 94551. You will then be sent a key to the observing hill gate (different than the Mines Road gate), a copy of your signed agreement, and directions to the site.

3. After receiving your key, contact a board member for mandatory orientation. This must be done either in person or by telephone, not by mail or e-mail. This is to ensure to our satisfaction that you have actually heard and understood the rules and have not just signed the agreement without reading it. After the orientation you will be given the combination to the gate. If the combination is changed or you forget it, it can be given to you only in person or by telephone by a board member, never via mail, e-mail, voice-mail, radio, or other media (because we have no control of who may see or hear the combination before you do).

All three steps usually can be conducted in person at any TVS general meeting or TVS board meeting, although it is preferred that the orientation be performed as part of a visit to the site.

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Patron Membership

After being a member of TVS for a year, and with the approval of the board, for an additional $40 per year you can become a Patron member which gives you access to The Jack Marling 17.5 inch Telescope located in the rolloff roof H2O building. This telescope is usually available for public viewing during the open houses.

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User Agreement Form

For a PDF version of the Agreement Form, click here.

In exchange for the opportunity to use the Hidden Hill Observatory (H2O) observing site, I ________________________, TVS member in good standing, agree to:

  • Pay a refundable deposit of $20 for use of a key to the observing hill gate. The key is the property of TVS and is not transferable and may not be duplicated. Deposit will be forfeited if my membership dues are delinquent more than six months.
  • Pay a $3 per car entry fee on each visit. I will put this money in the slot in the box/post to the south of the owner's house (or other location if changed by the ranch owners) before proceeding to the observing site.
  • Abide by all the rules established by TVS for the use of the site. I agree that these rules may be changed by TVS at any time. These include: No smoking, No fires, No camp stoves, Only red lights after dark, No music, No radios, No TV, No computer audio, No loudness, No littering, No leaving the hilltop, No alcoholic beverages, No pets, No illegal substances or activities, No firearms, No littering.
  • Drive extremely slowly and carefully while on the ranch so that I do not raise any dust from the dirt road.
  • Always close and lock the gate to the observing hill (this is a livestock control issue). Always leave the other gates as I found them. Never leave any of the TVS locks unlocked or the combination unscrambled.
  • Never loan my key or give the combination to anyone (including other club members -- only board members are authorized to do so). Never disclose the exact location or give directions to the site unless you are personally escorting someone.
  • Always personally escort any guests to and from of the site, and remain with them while at the site. Never arrange to meet any non-keyholding people on or near the ranch property and do not loiter or allow your guests to loiter on or near the ranch property. The closest acceptable meeting point is a bar/restaurant called "The Junction" near the junction of Mines, San Antonio Valley, and Del Puerto Canyon Roads, but meeting at the corner of Mines and Tesla Roads in Livermore is more desirable.
  • Be responsible for ensuring that my guests abide by all the H2O rules while visiting the site.
  • Relinquish my key(s) if I do not renew my yearly TVS membership or upon demand of a club officer.


By my signature below I show that I have read and understood the above conditions. I understand that the failure to comply with any of these conditions may result in the revocation of my privileges.

Signature____________________________ Date _______________ Key number________

Print Name: _____________________________________________ Issued ____________

Address: ________________________________________________

________________________________________________________

Phone____________________ e-mail _________________________


Return this form to TVS P.O. Box 2476, Livermore CA 94551, or directly to the key master, or bring it to a regular TVS general meeting.

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Orientation Lecture & Rules

These rules may be changed by TVS at any time.

The Hidden Hill Observatory is a wonderful dark sky site, and we are very fortunate that it is available for our use. It is essential that we maintain the goodwill of the people who work and make their homes on the ranch if we are to continue to enjoy access to the site. The ranch people get very little benefit from us and they are not particularly interested in astronomy. If by carelessness or accident we become an annoyance to them our access will end quickly. This is not a public park. We are there only at the invitation of the owners.

What follows may seem to be an excessive and overly detailed list of rules, but rest assured that this list was created to address and prevent specific problems that have arisen in the past. The rules cover two main issues 1) showing respect and courtesy to the owners, tenants, and workers, and 2) safety and consideration of others.

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The Rules

No dust. The most common complaint is that people drive too fast and raise clouds of dust. This dust settles on clothes on the clothesline, goes in open windows, and is a major problem everywhere. When on the dirt roads we must use extreme care and drive even more slowly than seems necessary. Sometimes, in very dusty weather, even 5 MPH is too fast. Remember you are driving through someone's front yard.

Always pay your $3 per car per visit, no matter how short your visit is or what the reason -- even retrieving lost items or performing observatory maintenance. The $3 pays for the right to pass through the ranch once. Driving through without paying is totally unacceptable.

Always close and lock the observing hill gate. That gate is for both the security of the observatory and for control of livestock. A closed but unlocked gate can be opened by livestock. Do not leave the gate unattended and open or unlocked for the next car, even if they said they would be down in two minutes. Always leave the other gates in the same state as you found them, open or closed, locked or unlocked. Always leave the TVS lock on the Mines Road gate locked and scrambled. Never lock a gate so that one of the other locks in the chain can no longer be used to open the gate.

Due to serious fire danger, no fires, charcoal, or outside camp stoves are allowed. Camp stoves can only be used inside an RV or trailer. This restriction is in effect all year. There is no water on the hill for fire fighting. Even one little fire would destroy our observatory and end our relationship with the land owners. Fire is such a concern in this area that even giving the impression that we are not being extremely cautious in unacceptable.

No Smoking. This applies to cigarettes, cigars, pipes, and any other form of smoking. If you are desperate you can smoke inside your vehicle, parked away from other observers, with the windows rolled up (so that a sudden gust of wind does not carry away burning embers) and using your vehicle's ash tray. Dropping butts and matches on the ground leaves the impression that there have been people smoking outside and they are probably not being sufficiently careful about fires. The fire danger is sufficient reason to forbid all smoking, but there are more reasons: Smoking ruins the fresh air outdoor experience for other people. Smoke leaves damaging deposits on optics. The battery recharger in the observatory emits hydrogen when operating which could lead to an explosion. No smoking of illegal substances, even in your vehicle.

No music, radios, TVs, scanners, computer audio, generators, electronic games, or other sources of noise (an exception can be made for hearing live coverage of an astronomical event of general interest at a reasonable volume level). If you must listen to something use headphones or listen in your vehicle with the windows rolled up. If other observers can hear it, it is too loud. These sounds disturb the tranquillity of the site, interfere with concentration, and attract the attention of people on the ranch, and nearby ranches. Cell phone and other radio conversations should be kept to a minimum.

No leaving the hilltop. You will soon be trespassing on someone's land if you wander around. You also risk meeting wild animals, spooking livestock, and possibly getting shot.

No alcoholic beverages. The use of alcohol interferes with following the other rules and makes driving unsafe.

No Pets. They not safe there as they could easily run off and encounter wild animals (such as mountain lions, bobcats, wild boars, coyotes, foxes, rattlesnakes, etc.), and they may annoy livestock or otherwise be a nuisance with their noise.

Do not tell anyone (even other members) the directions to the site, the name or exact location of the ranch, or the combination to the lock. Disclosing this information is reserved to board members. It is a recurring problem that someone learns about the site and wanders up there without escort or knowledge of the proper procedures and then proceeds to inconvenience and annoy the ranchers and astronomers. New visitors wishing to check out the site should attend an open house, or be escorted by a valid keyholding member.

Only red lights after dark. Try to park facing the exit if you are leaving early so that your backup lights are not used. Disconnect your car's interior lights or cover them with red filters if you need to get into your car after dark. Always check to see if someone is making a photographic exposure before leaving.

No littering, No illegal substances or activities, No firearms.

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