Geocaching - The Official Global GPS Cache Hunt Site

The Backbone Trail (BBT) is one of the jewels of the Santa Monica Mountains. Find all the caches along the trail, and you're eligible for the Spinal Tap!

Conceived decades ago, the Backbone Trail was originally to run from Point Mugu to Griffith Park. Mansion building outpaced trail development, and a continuous trail east of the 405 became infeasible, resulting in the almost-70-mile trail with its eastern terminus in Will Rogers State Historical Park. The entire trail is open to hikers except for an incomplete section near the Ventura/LA County line, with many parts open to bicyclists and equestrians.

One of the prime movers behind the BBT was the legendary Milt McAuley. Milt led hikes and volunteer trail maintenance crews. He was equally comfortable lobbying political figures to gain support for parks and trails, and negotiating with landowners for access. He wrote Hiking Trails of the Santa Monica Mountains, Wildflowers of the Santa Monica Mountains (for which he also drew the identification images), and of course a Guide to the Backbone Trail, along with books giving more details about the individual state parks. The books are widely available in local stores, especially Adventure 16 and REI, who deserve your patronage in return. Milt died at age 89 as Don and I were preparing Spinal Tap. We both express our gratitude for all he did for us and for our friends.

Naturally the BBT has been popular with geocachers as well. As of the publication of Spinal Tap, 88 caches were reasonably accessible from the BBT (including Spinal Tap itself), with a likelihood of more to come. (In fact, the next one was placed the very day Spinal Tap was published.) And this is even though some long stretches of the BBT pass through NPS lands where geocaches are not allowed, notably a stretch of about 25 miles between Sandstone Peak and Corral Canyon. You could find all the caches on a single BBT through-hike, though it's expected that most seekers will spend a lot of time enjoying many parts of the Santa Monica Mountains while making progress on the Spinal Tap.

The official list of caches on the BBT is Don_J's Backbone Trail bookmark list, known here as "the BBT list". (Also see map.) The list includes all active caches within roughly 250 feet of the BBT; see the bookmark list for details. If you notice errors or omissions in the list, send a message to Don_J. His word, not mine, is final as to the content of the list.

The basic rule is that you must find all the other caches on the list to be eligible to log a find on the Spinal Tap final. However, you are given some leeway so that you don't have to chase down caches placed just as you are trying to finish. Though you must find all caches on the initial BBT list, you don't have to find caches published later but within three months of your find log on Spinal Tap. Of course you are encouraged to find them all. Important exception: caches which are disabled due to environmental concerns are excluded for the duration of the disablement. These will be clearly noted on the BBT list.

The final cache location is not a secret or puzzle -- and of course it's on the BBT! When you have logged your finds on the prerequisite caches, you may visit and log a find on the final cache. As with all caches, you are required to physically visit the final cache and sign the log. Only those who have completed the rest of the BBT list are allowed to log a find on the final cache, though others are welcome to log visits.

The D/T for the final cache are 2.5/2.5. It's about 20'-30' from the posted coordinates, but only because posting the true coordinates might lead to confusion. It's close to the trailhead, which I haven't waypointed for you, since if you've found all the BBT caches, then you certainly know where the trailheads are! Ah, OK, if you need help with the trailhead, check it out on Trailheads in the Santa Monicas. There's a minor scramble to reach the final, and finding the correct route is important, justifying the ratings. The wrong route could be bad for your health. At the sharp turn in the trail, go a few feet up the drainage, make your way up to the rock wall that looms over you through the vegetation, and follow the wall up to a crack. Opinions will vary on whether this is a large crack or a small crack, but you've seen and probably passed through smaller ones on the way to other caches. You will need your hands and knees. The cache is in an open area at the top. It's also possible to go a short way past the opening and climb over rocks to reach the cache, but that route is probably more difficult than the crack.

Other rules:

New caches: to avoid a version of Zeno's Paradox on the BBT, you do not have to find very recently placed caches. Initially, this is defined to mean that if the publication date (the reviewer's publication log) is both a) later than the publication date of Spinal Tap, and b) within three months of your finding the Spinal Tap final, you don't have to go back and find that new cache. This is subject to change, but any change will only apply to caches published after the change.

The "date hidden", being completely under the control of the owner, is not used, only the date of the reviewer's publication log. Also, the date added to the BBT list is not used. Neither I nor Don_J can guarantee that caches will be added rapidly, though Don expects to maintain the list. This means that if you only watch the BBT list, your window on new caches could be smaller than three months. If you are nearing completion and this concerns you, you should set up notifications from geocaching.com to make sure you are alerted to new caches.

Disabled caches and caches believed to be missing are to be handled exactly as they are in other situations. They are not excluded from the prerequisites except as otherwise noted herein. You might simply wait for the owner to take action. When appropriate, you might contact the owner and offer to help. When necessary, you might post Needs Archived or contact a reviewer privately. These are the same options you have for any cache.

Environmentally disabled caches: there is one exemption for disabled caches. Caches which are disabled due to environmental concerns are excluded for the duration of the disablement. These will be clearly noted on the BBT list. Whether a disablement is for environmental concerns is solely Don_J's judgement. In such cases, the three-month rule does not apply at either end. Once a cache is placed in this category, you don't need it for the final until it is removed from the environmental concern category. However, once that happens, you also do not have a grace period unless the cache is still within three months of publication.

Prerequisite caches means all caches on the BBT list except the Spinal Tap final and caches excluded by the "new caches" and "environmentally disabled" rules.

Archived caches: You do not have to find archived caches, even if they have not been removed from the BBT list.

Prepublication finds: If you found a cache before publication of the Spinal Tap, it does count -- you are not expected to revisit caches you already found.

Hiders keepers: You get automatic find credit for caches you hid.

Claims: This is for fun and you are on the honor system. Issues about the validity of finds on caches in the list are between you and the cache owners.

Logging the final: You may only log the Spinal Tap final cache after you have logged finds on the prerequisite caches. You must log all your qualifying finds on geocaching.com. Non-completers are welcome to visit the final, sign the log book as visitors, and log notes to the cache page. If you visit the final before completing the prerequisite caches, you must revisit and re-sign the log afterward to log your find on Spinal Tap.

One special case: if you DNF (logged on gc.com) a prerequisite cache, then visit the final and log a note, and the cache you DNF-ed gets archived with no further finds, you may log a find on the final (as of the date of your visit) without revisiting it. The intent is to allow you to complete the series without waiting for the wheels to slowly grind, if you are willing to bet that your unfound cache(s) will be archived. Note that in this case you have still conformed to the rule that your visit to the final is after finding all prerequisite caches, so this is just an explanation and not an exception.

Terrain: Parts of the BBT are only accessible to strong hikers. As of publication, there are no caches on the BBT list which require physical skills beyond strong hiking. I reserve the right to exclude future caches which would require additional skills, such as rock climbing. The point is to keep this cache accessible to all strong hikers.

Difficulty: As is typical of hiking caches, the BBT list caches are generally easy to moderate in difficulty (as opposed to terrain). I reserve the right to exclude caches whose actual difficulty proves to unreasonably prevent cachers from completing the Spinal Tap.

Difficulty/Terrain: The listed difficulty and terrain (2.5/4.0) are the maximum you will encounter while completing the BBT list. This is the D/T in my judgement. Henry's Cache (the oldest on the BBT list by seven months) has a difficulty rating of 4.5, but this is a misclassification.

Follow the code: It's the GCxxxx code that matters. Occasionally cache names change, though I'm not aware of any on the BBT list changing.

Tracking your progress: The list below is generated automatically. Generally it will be updated each Tuesday, so if you're trying to figure out what you are missing, be aware of this delay. Tip: You can do a Pocket Query (assuming you are a premium member) on someone else's bookmark list. If you load the PQ results into GSAK, the result will show you exactly what you have and haven't found. Probably other offline caching software can provide similar results.

Cachers who have completed the challenge as of 2010-02-09:

Cachers with 25 or more finds as of 2010-02-09: