The south shore camping area of Lake San Antonio has been my "secret" observing spot for quite some time. I was first introduced to this site in 1991 and from that time through the summer of 1997 spent a few days most new moon periods observing there. I have been down there less frequently over the last couple of years since my former observing partner dropped out of the hobby and having been between telescopes (that's another story!). Nevertheless - I really like this spot and have had many of my finest nights of observing there. That being the case, I freely admit that my view of the site may be tinted. Certainly, the opinions expressed below represent only one person's opinion and should be treated as such. With those caveats, I offer my own analysis of the location.
General:
Lake San Antonio Park is located in southern Monterey county and is administered under that county'y park system. It is located 30 miles more or less due south of King City, west of Hwy 101, and adjacent to the Fort Hunter Liggett Military base. It is mainly dry, desert-like country of dry grass and scrub brush and sparse trees. Its main attraction (obviously) is the lake (actually a reservoir) and it appeals mainly to the powerboat/watersports crowd. The large Redonda Vista campground sprawls along the south shore of the lake and several hundred feet above it. It has good facilities - numerous showers, flush toilets, potable water at each camp site. When I first started going down there, we regularly set up in the "F"-loop of the Redonda Vista Campground (a portion of the campground that was fortuitously closed due to low park usage, but which the rangers granted us permission to use). This area covered a small knoll which represented the highest point of the south shore campground (about 1200 - 1400 ft if I remember correctly). If you will recall, this was at the height of the last drought period. Since the lake level was at all-time lows, the park was almost always sparsely populated and one could easily observe without bothering or being bothered by other campers.
With the return of the rains in the mid-1990's, the lake was restored to its normal level and people began to return to the park. All the campground was opened and it began to get more and more tricky to find a decent observing spot away from other campers, particularly during "peak" season. This together with the steady maturing of a few trees around the top of the F-loop began to seriously compromise observing trips. However, about this time, while lamenting this deteriorating situation to the head ranger, she suggested that we try the overflow campground that lay about 1/2 mile down the road from the main Redonda Vista Campground. The overflow campground is closed for all but the two or three biggest holiday weekends of the year: Memorial Day, Fourth of July, and Labor Day. They were, however, happy to let us use it (being good little boys and girls and sharing the occasional look through your scope works wonders with park staff!).
The overflow campground sits well back from the park road and is loosely centered around a "baseball field". OK, it is a large, flat, hard-packed and occasionally cratered field covered by dry grass with a forlorn backstop at one corner. It looks like an awful place for a baseball game, but it is excellent for setting up astro equipment. The grass is cut every so often so
The observing area of the overflow campground at Lake San Antonio.
is usually not so long as to be a nuisance. It is very large and could easily accommodate a large group of observers. Although lower in elevation than the F-loop knoll by perhaps a couple of hundred feet, the horizons are excellent. I'm no good at estimating angles, but I doubt the surrounding terrain rises much above ten degrees at any point. The facilities are more primitive than the main campground but there are still portapotties and potable water at the campsites. But best of all, you can go at any time of the year (excepting the weekends mentioned above) and have the place to yourself. I was told by the rangers that there were other astronomers that used the site occasionally, but I have never met anyone else. Traffic is little bother. As I said, the baseball field is set well back from the road, so the headlights of the odd passing car are of little consequence. Traffic flow is very low - the park is well of the beaten path, and the park road is a windy loop so there are few "joyriders". I have never experienced anyone wandering into the overflow campground looking for mischief.
The sky is typically very dark with limiting magnitudes well it excess of 6 (I'm no good at estimating magnitude limits either). The only noticable but small light dome is that of San Luis Obispo, some 60-70 miles south-southeast. Indicative of the quality of the sky, I have frequently observed the milky way to take on the "grainy" appearance of a myriad individual salt grains cast across a piece of navy blue velvet, even down as low as Saggitarius. Air traffic is substantially less than Pacheco, although on occasion the military will conduct maneuvers at Hunter Ligget to the northwest. This is accompanied by occasional dim flashes similar to heat lightening and the faint thunder-like rumble of heavy weapons fire. It is of little consequence for visual observing, but might be of more concern for photography. Nonetheless, this is relatively infrequent and certainly the exception rather than the rule.
As pointed out previously, it is a bit of a haul from the Bay Area. It usually takes 2-3 hours to get there. However, I find the drive to be easy and pleasant. The last 40 miles or so are along the J14/Jolon Road, a well kept but sparsely travelled two-lane highway condusive to ~60 mi/hr driving. Honestly I find it a bit to far for a comfortable 1-night observing run, but I think it is well worth the travel for 2 or more nights. Beware: It can be beastly hot down there in the summer months - 100 degrees is not at all unusual and I have seen the occasional 110+ day down there. When a breeze kicks up it can be like opening the door of a blast furnace. I typically spend the layover day(s) dozing in the shade with lots of ice water handy. I, myself, like it. It is as much a part of the purification of the mind and soul as the observing. But be ready for it.
Listed below are what I see as the main "pros" and "cons" of the site:
Pros:
*very dark skies.
*excellent, large observing site w/ great horizons.
*very nice location (if you like that type of country) with nice hiking/swimming available (my wife and kids have accompanied me a couple of times and loved it).
*very agreeable and friendly park staff - accommodating to astronomers.
*relatively private - very low occurrence of traffic/rowdies.
Cons:
*long drive (~150 miles from San Jose).
*relatively low altitude, occasionally susceptible to fog.
*pricey - ~$16/night camping the last I knew.
*Can be BEASTLY hot - 100o+ degree temperatures are common during the summer and I have seen 110o+ temps on several occasions during July - October.
If you have any remaining questions about this site, I'd be happy to answer them. Just drop me an email at: hudginsclan@mindspring.com.