Dinosaur Point and other South Bay observing sites

[Lance Pickens]

Hi Everyone,

Curious about other observing sites here in South Bay. Henry Coe is great would love to see other options especially with the marine layer clouds tending to cluster just this side of the mountains. Every time I check the weather always looks clearer near Pacheco eastwards on any given night. Anyone have experience or thoughts observing east of Henry Coe?

Cheers,

Lance

[Brad Templeton]

I've been to Dino point but not recently.  Nice and dark to the south.  But the rangers became unfriendly, so you are limited to the upper lot, which is not behind the gate so members of the pubic will sometimes drive in, headlights on.     It's the same driving time as Coe, but darker (except to the east.)   Sometimes there is wind.

You have perused the observing site list?

[Peter Natscher]

Pacheco SP -- Dinosaur Point boat launch parking lot is not available for nighttime astronomy anymore.  That access through the gate at the top of the hill at Pacheco SP gets locked for the night by sunset.  You are now limited for astro use the Pacheco SP trail heads parking area at the top of the hill outside of the gate next to the exit road for Dinosaur Point on Rt 152.

[Mark Wagner]

It may be that the rangers are ok, but there is no point person(s) for TAC to coordinate with the rangers.

It was a totally open site prior to 911, which resulted in restricted access. Jamie knows the most on this topic.

My take is it's FP or Coe for near the South Bay, for elevation when the marine layer is in.

I went to a nice private 2000 ft elevation site Wednesday, south of FP.  Darkness equal to LS or Pinnacles East.  Maybe darker, I need more visits to better quantify.

On Friday, May 15, 2026 at 1:19:15 PM UTC-7 Brad Templeton wrote:

[Muriel Dulieu Holzer]

Hi Lance, 

Have you checked where the local astronomy clubs meet? 
San Jose Astronomical Society (SJAA), San Mateo County Astronomical Society (SMCAS), Tri-Valley Stargazers (TVS), and Fremont Peak.
I am only familiar with TVS, their H2O site is North of Coe. They also meet at Del Valle I believe.

-Muriel

[Mark Wagner]

Lance,

I don't think you'll find anything Eastward of Pacheco, it's just central valley which I don't think works at all 

And I think TVS and Peninsula are outside your parameters.   I know you're on CDSE which has a spreadsheet of many sites that are not so well known, to the south of the bay area.  They may help.

On Friday, May 15, 2026 at 12:29:18 PM UTC-7 Lance Pickens wrote:

[Jamie Dillon, DDK]

And Lance, along with the other useful things people have said, our TAC observing sites list is the result of years and looking and careful updating.

https://observers.org/observing-sites/

DDK sez peruse it!

[Lance Pickens]

Thanks everyone for the responses. I think I'm looking for some
alternatives to Coe not only for the weather but ease of access, that
and the area between Coe and Pacheco does look interesting. Before
joining TAC, I mostly observed at Coyote Lake, which worked really
well, but it seems less friendly lately according to the site list
here.

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[Mark Wagner]

Lance, perhaps you want to find out what you can do at Dowdy Ranch - although it appears to have some camping restrictions.

[Brad Templeton]

What's the situation at Rancho de Oro?   SJAA uses it for their dark sky local parties.  It's Bortle 4, though brighter than Coe, but you see the milky way etc.    But most importantly, it's about half the drive time of Coe or Dino Point, which all require 2 hours round trip of driving.   Have people talked to the rangers about how much bureaucracy there is there?  SJAA nights there are a big deal, they get so many people they have to do registration and turn people away.

[Lance Pickens]

Thanks Mark!  Dowdy Ranch looks like it might work, I’ll reach out to the ranger soon and talk to them. for this week I’m going to head to Coe until I have a chance to drive down and explore Dowdy

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[John Pierce]

On Sun, May 17, 2026 at 11:20 AM Brad Templeton <bra...@gmail.com> wrote:

What's the situation at Rancho de Oro?   SJAA uses it for their dark sky local parties.  It's Bortle 4, though brighter than Coe, but you see the milky way etc.    But most importantly, it's about half the drive time of Coe or Dino Point, which all require 2 hours round trip of driving.   Have people talked to the rangers about how much bureaucracy there is there?  SJAA nights there are a big deal, they get so many people they have to do registration and turn people away.

I'd be worried if it gets out that TAC is doing star parties there, they'd be packed with those same SJAAers 

I went to one of those, and found the horizons rather restrictive.     Its Rancho Cañada Del Oro, run by the Santa Clara Open Space Authority, and technically it closes at sunset. 

https://www.openspaceauthority.org/preserve/rancho-canada-del-oro

[Joshua Hutchins]

SJAA runs two types of events at Rancho del Oro (RCDO)- public star
parties (Starry Nights), and member-only observing nights. The public
star parties aren't for everyone to bring their own telescopes; you
need to arrange with them beforehand if you will be bringing your
telescope and doing outreach. The member observing nights are for any
member to attend. The site can fit 10 or 11 observers, so there are
signups ahead of time, but it rarely fills up in my experience.

The horizons are not great, but the hills do block some of the nearby
light domes. It also tends to get more dew. The site's advantage is
its convenient location, and if you are an SJAA member, it is open on
many dark moon nights- it was open Sunday, Monday, Tuesday, Wednesday,
and Friday this past week.

I'm not involved in the bureaucracy for getting the permits, but the
club does have permits to run the members observing nights and stay
past the normal closing time.

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[Brad Templeton]

Yes, horizons are not ideal there but there is a decent amount of sky.     Apparently gets a bit cold.    TAC would not advertise, obviously.  SJAA has promotion and sign-ups.    Not that much promotion actually and they get a crowd, though.      I don't even mind the public, except for the fact they can't follow dark site procedures with their headlights, which is the main fault with the upper lot at Dino point.   (Otherwise upper Dino requires no advance prep, you can just go.  Of course, that's not unrelated since having a gate requires bureaucracy but it protects from the public.)          The issue with Dowdy is you start pushing the time limits on that.    I'm going to see nearly 3 hours round trip driving to Dowdy, vs. 2 hours to Coe or Dino, and 1hr 10 minutes to Canada Rancho de Oro or Monte Bello.

It does seem hard to find a dark lot at the end of a road, with either no gate or a gate we can get the combo to.     I guess Oak Ridge is that.   There are a few places like school and church lots but they tend to have lighting.

[Mark Wagner]

I'd be surprised if TAC gained access to RCDO, as it is not a real entity.  TAC is vaporware (other than LCO Inc./GSSP).  Even Montebello which is under different management than RCDO requires permits, but those are (to my knowledge) to individuals - even for group use.

[Mark Wagner]

Clarification on Use of RCDO ((posted for Joe Fragola):

I was going to reply to the TAC thread “Dinosaur Point and other South Bay observing sites” to clarify the information regarding access to Rancho Canada del Oro Open Space Preserve.  When i attempted to reply I had an error message saying that I don’t have permission to post to the Group.  That’s not important, since I’m more of an interested bystander in regard to reading posts on the TAC Google Group.  This is a rare occasion where I saw a post that I can help get more accurate details out to anyone who is interested.  Since I don’t have permission to post, I thought I could send you the info and you could pass it on for me.

I’m an SJAA Member and the current Program Lead for the joint OSA/SJAA monthly public star parties at RCDO called “Starry Nights”. I also coordinate dates with the OSA for our monthly Members observing nights, mostly at RCDO.

Some specific clarifications to what has been posted:

From Brad Templeton…"SJAA nights there are a big deal, they get so many people they have to do registration and turn people away."

Clarification: This isn’t quite true.  Several years ago, before my involvement with Starry Nights star parties, there was an instance where an unusually high number of attendees showed up and parking space was exceeded.  I heard there was a mess with traffic trying to come in on Casa Loma Rd, while others were being turned away due to no available parking.  After that incident the OSA established the registration process in order to manage the number of cars in regard to available parking.  In my 3 years of coordinating SJAA volunteer resources there has never been an occasion where people were turned away since the parking situation has been managed through the registration process.  Last Saturday, May 9, we had 92 attendees which amounted to maybe 60 - 70 cars plus Guests.


From John Pierce…"I'd be worried if it gets out that TAC is doing star parties there, they’d be packed with those same SJAAers.”

Clarification: Don’t worry, we have plenty of scheduled Members-only viewing nights at RCDO to accommodate our Membership.  We can squeeze in 13 cars to park within the telescope setup area.  If we have more than 13 requests to attend we shuffle things around with people who have lighter, portable smart scopes and don’t need to take a spot along “telescope row”.


From Joshua Hutchins…he had a good summary of SJAA activities at RCDO, with an exception - "I'm not involved in the bureaucracy for getting the permits, but the
club does have permits to run the members observing nights and stay past the normal closing time.”

Clarification: We don’t have a permit.  The authorized docents have keys to the entrance gate for closing at the end of the night. Beginning in 2025, the OSA required some specific training be completed to become a “qualified Astro Docent”.  The training is required for telescope volunteers who interface with the public at Starry Nights, as well as for those Members who host the monthly observing nights.  We currently have 37 “qualified Astro Docents”, however there is a subset of 9 people in that group who have the key for the entrance gate.

From yourself…"I'd be surprised if TAC gained access to RCDO, as it is not a real entity.”

Clarification: I think the required OSA qualification training which includes getting finger printed and attending a 4-hour Interpretive Host Training class is well beyond the limits of interest to any TACos.

Some final points…..

One of the “perks” for SJAA as a result of providing telescopes/large binoculars to support the monthly Starry Nights events is that the Club Membership is granted access to RCDO (and other OSA managed properties) after sunset for nighttime viewing. OSA Field Techs will come by around sunset to lock the entrance gate if there are still unauthorized people at the site.

I coordinate monthly dates with the OSA and need them to confirm that we have not requested a night that conflicts with any of their other scheduled after-hours activities at RCDO.  In the past we’ve been denied due to a scheduled “frog count” in the nearby creek that runs through the OSP.  The OSA sometimes has night hikes scheduled there. In the Spring there are times when the OSA has a group of Preserve Stewards on site to inspect hiking trails for obstructions and erosion following winter storms, so access is closed to other events. These scheduling conflicts are rare, but have occurred.  In the past when there’s a conflict we’ve switched to another OSA site that is available.

As mentioned in one of the posts, a primary “pro” for using RCDO is the easier drive. So despite some of the “cons” (limited horizons and skies that are not as dark as most of the TAC observing sites), we like it well enough.  Plus it’s a better solution for newbies who are not familiar with nighttime light etiquette, although there hasn’t been anyone who has shown up with a regular white light flashlight, YET  And maybe we’re actually helping the overall astro community by making the new people get more comfortable so they “graduate” to the larger, more serious astronomy star parties.

I think that covers it, and certainly not as interesting as reading a TAC OR.  But I wanted to help explain the process and correct some mis-information.

I’ll return to “lurking bystander mode” now.

Joe Fragola

[Brad Templeton]

Thanks for all that info.  When I wrote that people are turned away, I mean that the registration web site turns them away before they come.  I had no info on whether people were turned away at the gate.  When I have come they didn't bother checking registration.

I think if I could describe the ideal site it would be a short drive away, Bortle 1, clear horizons,  have no lights near it and no non-astronomer cars who drive up to it, but which we can get into without advance notice and leave whenever we want.     But we'll settle reluctantly for Bortle 4, under an hour away, and we put up with having to arrange things 1-2 days in advance (sometimes same day) and needing permits, or somebody who has to escort people in and out etc.      Now, if a group has enough "Qualified Astro docents" then that could be good, as one could see the sky is clear and announce an OI and go.      Even here where the weather is very predictable, having to arrange a day or two in advance has a risk.

I presume that the coordination on dates is for times when a big crowd is coming in.  Half a dozen astronomers in the parking lot should not disrupt anybody. 

1. Coe:  1 hour drive time (south bay), rangers need advance notice, get there before sunset, darker Bortle 4, leave when you want.
2. Dinosaur Point Upper:   1 hour 9 minutes, show up and leave whenever you like, Bortle 3 to the south, public may drive in with headlights, windy certain times of year
3. Dinosaur Point Lower:   A touch longer, strict control of access and exit, if the rangers can even be convinced to let us in.
4. Monte Bello:  In theory permit must be requested 2-3 days in advance, but often they will approve same day.  Brighter Bortle 4, good to west.   You get the combo, come and go as you like, but if caught without permit could be trouble.   35 minute drive from south bay
5. Oak Ridge: 32 minutes, decent skies, private.  Must pay annual Oak Ridge fee to PAS plus membership in PAS -- $100 per year
6. Southern Coe: Being investigated, 1 hour 25 minutes drive.

[John Pierce]

Speaking of South Bay sites, sigh, the Santa Cruz Astronomy Club has lost access to Bonny Doon Airport, again :(      The past year or two, its been available for club members only one night per month, but there's a new tenant, and that privilege has been taken away.

history:    for decades, the owners of the BD Airport allowed SCAC and guests access 1 or 2 prescheduled nights per month, and there were some nights that were spectacular up there.  The site is at 2000 feet, with low horizons due south to northwest, and a tall stand of trees blocking the bay area sky glare to the north and east.   There was room there for dozens of astronomers, and easy road access off Empire Grade.   When the current owners bought the airport, they locked SCAC out entirely, and it took a fair amount of negotiation to restore the recent 'member only' privileges a couple years later.