Eaton Canyon is located in the mountains (Angeles National Forest) N of Pasadena, California, USA. The term "Upper Eaton Canyon" is not well defined but here it means that portion of the canyon above the last waterfall of the lower canyon which is just downstream from the defunct Sugar Bowl campground located just ENE of the 2647 ft. elevation peak shown on the Mt. Wilson topographic map. The first waterfall of the lower canyon is frequently visited by hikers. There is a series of waterfalls above this first one, then a stretch with mostly no waterfalls, and then another series of waterfalls, the last one of which marks the start of upper Eaton Canyon at the now defunct "Sugar Bowl" campground.
Hiking in from Altadena, these two routes go up the slope of the front range in back of Pasadena on trails/fire-roads which are either W or E of the canyon and then descend many hundreds of feet into the upper canyon. Each utilizes a different segment of the "Idlehour Trail" which descends into the canyon from both the E and W sides. The one from the W side starts from a point not far from the ruins of the old Mt. Lowe Tavern from a point on the abandoned "One Man and Mule" railroad, about half way between the tavern ruins and Inspiration Point. The route from the other (E) side of the canyon starts from a point on the Old Mt. Wilson Toll Road about 1.2 miles beyond Henninger Flats (See Thru Henninger Flats). One may also access the two staring points of the Idlehour Trail by driving up on the paved Mt. Wilson Road from Red Box and then hiking downhill on dirt fire roads to meet the Idlehour Trail at either its western or eastern terminus.
It can be a little confusing getting thru Henninger flats on the old Mt. Wilson Road since there are a few junctions with other roads. But there should be signs to help you stay on this road as you walk thru the Flats. It's also possible to take a shortcut thru the upper campgrounds (see next paragraph). To follow up the Mt. Wilson Road thru Henninger first hike past the small buildings (one is a museum/residence) at Henninger Flats on the Old Mt. Wilson Toll Road. After 0.2 miles you come to the first Y road junction at which you make a sharp right turn. After about 0.2 miles more there is a road that veers off to the right (leading to the upper campgrounds at Henninger) which you avoid taking. At this point the Mt. Wilson Road starts to swing around to the left and you wind up walking in the opposite direction. Avoid taking a branch road that veers to the left and descends to a reservoir.
As an alternative to the above, one may take a shortcut thru the upper campgrounds. The lower campground is the one that you see to your left as you are just entering Henninger Flats (from Pasadena). The first building you come to (on the Mt. Wilson Road) is a restroom a little off to the right. You walk up towards the restroom and take a trail that goes up to the upper campground (should be a sign) and then continue up further to the 2nd upper campground called Fuji Camp. From the high point of Fuji Camp you turn left and walk up a dirt road past the last campsite and meet the Mt. Wilson Road as mentioned above. For a slightly shorter shortcut you don't start on the trail at the restroom but instead start up higher on a poor trail which takes off from the Mt. Wilson Road shortly before you get to the restroom. It starts at the high point on the Mt. Wilson Road, close to the large sign announcing Henninger Flats but this "trail" may be partially overgrown with vegetation.
After 0.3 miles beyond the reservoir (that you didn't descend to) you reach the top of the ridge separating Henninger Flats From Eaton Canyon. It's a T junction where you enter the bottom of the T and turn right to continue on the Mt. Wilson Road 0.4 miles to meet the Idlehour trailhead. But if you want to descend into Eaton Canyon further W, (on a much worse trail) turn left at this T. See ` Via Henninger Flats, Above Sugar Bowl to Idlehour
These routes are all off-trail routes. The most difficult is Access Via the Lower Canyon from Altadena, which has waterfall obstacles. Another of intermediate difficulty, the The Extreme Upper Canyon Route, is the opposite of the lower canyon route: One drives up most of the way to Mt. Wilson and then descends steeply down into the headwaters of Eaton Canyon. The third and easier off-trail route goes Via Henninger Flats, Above Sugar Bowl to Idlehour instead of using the Idlehour trail from the Mt. Wilson Toll Road. This route enters the canyon about a mile below Idlehour Campground but it's currently in pretty bad shape (and more difficult than the two on-trail routes).
One may drive up the paved Mt. Wilson Road to about half-way between Red Box and Mt. Wilson and then after hiking on the Mt. Lowe fire road a short ways, hike down a slope into the upper reaches of Eaton Canyon. Then it's down the trail-less canyon to meet up with the Idlehour Trail at its furthest point up the canyon. See details at Upper Eaton Canyon
Access to the upper canyon via going up the canyon from Altadena is made difficult by some waterfalls and a couple of pools in a narrow canyon where one needs to wade or swim thru water. During the 1930's it was much easier since the Pasadena Water Dept. had constructed a fine trail with wooden staircases around the first series of waterfalls. This trail was closed to public use in the early 1940's. During World War II there was both a fence and a guard to prevent people from entering Eaton Canyon at the Old Toll Road bridge in Altadena. Sometime after end of that war, it again became possible to use this trail, but then the staircases started to deteriorate. Eventually this once fine trail was mostly demolished (it was claimed to be dangerous due to the rotting wood staircases). But parts of it (except for the wooden staircases which are gone) can still be used (with some risky spots) to get above the first series of waterfalls (there are more waterfalls later on).
See Lower Eaton Canyon for a detailed description of this route by Christopher Brennen. But unfortunately, it describes a hike from the upper canyon to Altadena via the lower canyon. This is the opposite direction to the route one would follow to get from Altadena to the upper canyon. See also Canyoning: Eaton Canyon by Jason Hollinger.
It may be possible to go up thru the lower canyon to the upper canyon without bringing any ropes, provided that a fixed rope used to climb one waterfall is still there and safe to use. To avoid the upper series of waterfalls one hikes up the NE slope of the canyon side to reach what Brennen calls "Telephone Flat" and I call the "parking lot" described in Via Henninger Flats, Above Sugar Bowl to Idlehour. Then one continues on the poor trail from this defunct parking lot to the Sugar Bowl site in the canyon and then up the canyon to Idlehour. Last time I started on this route from Altadena the "trail" around the popular first waterfall had deteriorated and I was afraid to continue alone.
Unless you are going to descend waterfalls using a rope for rappels, I would not advise doing any hike down the lower canyon unless you first go up it and note the exact route you take. I once met some people who were going down the lower canyon and were stranded on a ledge they had slid down to but were unable to climb back up. They had to be rescued by helicopter. Their reckless act amounted to "burning their bridges behind them".
The barrier imposed by waterfalls of the lower canyon (before the Pasadena Water Dept. built the trail) likely resulted in few people visiting the upper canyon until the 4 ft. wide "New Mt. Wilson Trail" was opened in 1891 (which follows the route of the existing Old Mt. Wilson Toll Road). Later, in 1907, this trail was turned into a narrow road by widening it to 10 ft. (to 12 ft. in 1917) and became what is now the old Mt. Wilson Toll Road which today provides access to the upper canyon via the Idlehour trail which starts at a sharp bend (switchback) in the Toll Road about 1.2 miles beyond Henninger Flats. The toll on the wide trail from Altadena in 1891 was 25 cents for a hiker and 50 cents if on horseback. When was a trail built going into the upper canyon from this route? Note that there have been three routes to access the upper canyon from the Toll Road: one going via the Idlehour trail, another going down from Henninger Flats to Sugar Bowl campground, and the third (almost like the second) bypassing Sugar Bowl on a now defunct nearly level trail up the canyon to Idlehour. See Via Henninger Flats, Above Sugar Bowl to Idlehour
From the time this route was completed (perhaps in the late 1930's by the CCC ?) until the trail portion was closed in the mid 1970's, this route was competitive (for hikers) with the Idlehour trail. But if you were a cabin owner and had permission to drive on fire roads, it was by far the easiest route into upper Eaton Canyon since one could drive into upper Eaton canyon from Henninger Flats until one reached a parking lot a little over 300 ft. above the stream. From there, after hiking up the canyon about a mile on a nearly level trail, one reached the Idlehour Campground. Today, the road into the canyon has turned into an overgrown trail and most of the old trail from the parking lot to Idlehour has been abandoned.
But it's still possible to approximately follow this route today by descending to the streambed from the overgrown parking lot and then by hiking up the trail-less canyon to Idlehour. It takes a lot longer but it's more fun than the Idlehour trail route. This canyon route was shown as a trail on the 1939 topo map while the nearly level upper trail (now defunct) isn't shown at all.
Now for a more detailed description of the route using the Mt. Wilson topographic map (topo) (Be sure to read the next paragraph if you don't have the topo). First find Eaton Canyon and Henninger Flats (about a mile S. of the canyon on the old Mt. Wilson Road). About a mile N (and slightly to the W) of Henninger Flats and only about 0.1 mile from Eaton Canyon is a minor peak with a 2647 (feet) elevation mark. Just about 0.1 mile ESE of this peak, in a little saddle, is the overgrown (defunct) parking lot mentioned above where a road used to become a trail. Today it's where an overgrown road becomes an abandoned trail. The topo shows neither the road nor the trail at the parking lot site, but the topo does show the start of the road N of Henninger Flats that leads down to the old parking lot. It's shown as a dead-end road only about 0.2 miles long which runs E-W and ends at a tributary of Eaton Canyon (Esme Canyon but the topo shows this canyon but without a name). The overgrown road to the parking lot (not shown on the map) continues from this tributary, approximately following the 2600 contour but going slightly downhill so that it eventually crosses over this contour. There's an abandoned forest service telephone line along this road (which once went to the Mt. Lowe Tavern ruins) with some downed telephone poles and green corroded copper wires lying on the route (don't trip on them). Thus Christopher Brennen, the author of Lower Eaton Canyon named the old parking lot "Telephone Flat".
If you don't have a topo map and want to go from Henninger Flats to the old parking lot (and even if you have a map but want to trace the route) here's a guide to the route. Pass thru Henninger Flats until you reach the T junction about 0.7 miles beyond the museum building at Henninger Flats (See Thru Henninger Flats. Turn left at the T. After 0.1 mile you take the right branch as the road forks. Then go about 0.3 miles more, looking for an unmaintained road to take that branches off to the right and heads E (almost reversing your previous direction) and descends down into Esme Canyon, a tributary of Eaton Canyon. Cross this tributary and continue on the slightly downward overgrown trail along the old roadbed to the road's end at the overgrown parking lot.
Now you'll hike E from the parking lot along the starting section of the old trial to Idlehour which is almost level. This parking-lot-to-Idlehour trail was not well maintained in the past and in the 1970's developed narrow spots that were dangerous due to the steep drop offs to the canyon floor. A "trail closed" sign was posted and the trail abandoned. But this trail had (and still has --sort of) a branch trail which goes down to the stream to what was Sugar Bowl Campground just above the last waterfall in the lower canyon. This down trail starts about 0.1 miles from the parking lot and you can still use this section of the trail. But the down trial isn't as easy to find now as it used to be. Don't start descending too soon or you could wind up below the last waterfall instead of above it. This down trail always was steep and is even steeper now since it isn't maintained (switchbacks have disappeared). The Sugar Bowl Campground was on the N side of the streambed a little upstream from where the "down trail" meets the canyon bottom.
For hiking the opposite direction, if you are in Eaton Canyon at the Sugar Bowl site and want to hike up, go down the canyon on the S side of the stream until you find that you may need to use your hands (which means that you are approaching the last waterfall of the lower canyon. Go back up the canyon from here a short ways until you see a route climbing up the S. side of the canyon that people and animals have used. It's the start of the steep route up to the old parking lot.
To get between the Sugar Bowl site and Idlehour today is slow going via a trail-less canyon. When the parking-lot-to Idlehour trail was in good condition, one could get from Sugar Bowl to Idlehour faster by first taking the steep "up trail" and then utilizing most of the almost level parking-lot-to-Idlehour-trail to reach Idlehour. Today, parts of this trail still exist, but it's likely not feasible to get all the way to Idlehour via it. When it was open for use in the 1950's, it seemed that upon nearing Idlehour, this trail climbed a little and then descended to Idlehour, following a route a little above the 2600 ft. contour on the topo map.
There once was another way to reach the "parking" lot above defunct Sugar Bowl Campground and the last waterfall of the lower canyon. One hiked up the Mt Wilson Toll Road about 2/3 of the way from Altadena to Henninger Flats. Then one left the road and went E on a slightly climbing trail to the parking lot. The author took this trail in the late 1970's and found it to be in poor condition (especially as it neared what the author thought was the parking lot --he turned back at this point). But it now seems to have vanished. Since the terrain near the parking lot is almost vertical, it would be dangerous to try to follow this old route.
In ch. 16 of "The Mountains of California" by John Muir (founder of the Sierra Club) he describes his 1877 backpacking trip across upper Eaton Canyon. This is apparently the first published account of this "basin" as Muir calls it. The exact route he took is not clear but he first hiked up to the top of what has been called "Muir Peak" (elevation 4688 ft. on the topo map), following the ridge on the W side of the canyon (perhaps on the route of the old "Lone Tree Trail" which goes past elevation mark 3681 ft. on the topo map). Note that later topo maps show Muir Peak (4714 ft.) to be over a mile NW of this 4688 ft. peak that Muir likely climbed. He then descended into "a tributary" of upper Eaton Canyon and camped there overnight. It likely was the same tributary that the Mt. Lowe-to-Idlehour-Campground trial descends into and crosses when it goes from the Mt. Lowe Tavern campground into upper Eaton Canyon.
Muir spent a couple of days in the upper Eaton Canyon area as he mentions his 3rd campsite. (His 1st campsite was at the mouth of Eaton Canyon, perhaps not far from the old toll road bridge.) He also mentions following bear trails where bears had made their way thru the underbrush and in some cases left hairs on branches as they made their way thru tight spots. He sometimes had to crawl on all fours. His description of what must be the waterfalls and cascades below the defunct Sugar Bowl campground (below Idlehour) is: "My third camp was made near the middle of the general basin, at the head of a long system of cascades from ten to 200 feet high, one following the other in close succession down a rocky inaccessible canyon, making a total descent of nearly 1700 feet. Above the cascades, the main stream passes through a series of open sunny levels ..."
It one checks the topo map and Brennen's , Lower Eaton Canyon its clear that Muir exaggerated. None of the falls are anywhere near 200 ft. high (the highest one is about 50 ft.) and the series of waterfalls and steep streambed below Sugar Bowl drops a total of about 500 ft. until the canyon opens up for a wide level stretch about 1500 ft. long. Even the total drop in elevation from Sugar Bowl Campground to the bottom of the first waterfall, the one that many people visit today near Altadena, is about 1,100 feet. So Muir's 1700 feet is actually more like 500 feet (or 1,100 feet if his "close succession" is erroneous).
However, Muir could get away with such exaggerations since there was no one in those days in the sparsely settled Pasadena area who wanted to spend days roughing it in the chaparral to check up on him. And this isn't just an isolated instance of Muir's proclivity to exaggerate since I recall reading something in the Sierra Club magazine about other Muir exaggerations (need reference). One lame excuse Muir might give is that since he didn't have a rope and thus didn't actually descend the various falls to find out their height. But he shouldn't have given an "estimate" four times larger than the actual.
No mention is made as to what route he took to exit the canyon and return to what is now Altadena. Could it have been via what is now called Henninger Flats since he claims to have traversed the basin from W to E ? It's possible that Henninger Flats was occupied at that time since a Peter Stiel had homesteaded it sometime before 1884 (the year Henninger began to squat there).
Muir saw a potential economic use of Upper Eaton Canyon as part of a large "bee garden" to produce honey (obtained by bees from the native flowers) for beekeepers. In fact his chapter XVI, which contains this brief account of his exploration of the upper reaches of Eaton Canyon, is entitled "The Bee-Pastures" and is mostly about bee-pastures elsewhere in California.
In 1913 (1912 per another source) the Forest Service opened the "Eaton Canyon Tract" for the construction of "summer homes" in the part of the canyon above the last waterfall. This was only about 5 years after the Angeles National Forest was established. It's likely that most of the cabins were built there in the 1920's after the widening of the Mt. Wilson Road (toll) and the US was in boom times of the "roaring twenties". The land on which the cabins were constructed was leased from the Forest Service for a limited time to the cabin owners (leaseholders) for an annual rental fee. Events like failure to maintain the cabin, destruction by forest fire, failure to pay lease fees, etc. could lead to cancellation of the lease. Eventually, the leases on all cabins were cancelled one way or another.
On the 1939 topo map (Mt. Wilson) it shows 16 cabins in upper Eaton Canyon (except 3 of these were several hundred feet up tributary canyons). There were 2 cabins below Idle Hour, 10 more about 0.4 miles up the canyon from Idlehour (one a few hundred ft. up a tributary), 2 more just before the junction with Deer Park Branch, and 2 more several hundred feet up the Deer Park Branch. A newer topo map shows still another cabin just above Idle Hour Campground.
Today most all of the cabins are gone. What remains today are the stone foundations, chimneys, and sometimes lower parts of walls which were made of stone. But in the 1940's several of the cabins were still in use, especially the ones on (or close to) the Deer Park Branch.
In the late 1930's and into the 1940's there were 3 public campgrounds for backpackers in the upper canyon: Sugar Bowl, Idlehour, and Yucca Flat. Going upstream from the top of the final waterfall of the lower canyon, one encountered first Sugar Bowl (only a few hundred feet or so upstream from the waterfall), then Idlehour (about a mile further) and finally Yucca Flat where the main trail leaves the canyon, heading W toward Mt. Lowe. Today, only Idlehour remains. These 3 campgrounds were likely built by the CCC (Civilian Conservation Corps) during the depression years of the 1930's. They all had stoves and picnic tables (except that Yucca Flats may have had no tables).
Who used these campgrounds? Both times I camped at Idlehour in 1949 with another boy, we were the only ones there. So the campgrounds may not have been heavily used. I'm guessing that they were predominately used by adventurous teenage boys, including at least one Boy Scout troop (that I knew about).
From 1915 until 1929, this was "Camp Idle Hour", a resort where one could pay to stay overnight and eat meals. Then in the 1930's it became a free public campground and remains so today.
Sugar Bowl was located a short distance above the last waterfall, a little less than a mile downstream from Idlehour campground. It was on the N bank of the stream. See Henninger Flats, Above Sugar Bowl to Idlehour for routes to hike there. It's life as a campground was short and by the late 1940's it had been abandoned as a campground.
The Yucca Flat site is easy to find since it's right on the existing trail to Mt. Lowe. It's on the W. side of the canyon, but not real close to the stream. When going up Eaton Canyon on the Idlehour trail, at the location where it turns turns W to leave the canyon and head for Mt. Lowe, follow it a few hundred ft. to a level bench with Yuccas and you are at the abandoned campground site. It's away from the streambed and at the far edge of the canyon.
In 1949 when I was 15-16 years old I went with another boy on a couple of backpacking trips into upper Eaton Canyon. On the first trip I took my army surplus blanket sleeping bag and slept terribly since I was too cold. For the next trip, I bought an army surplus down-chicken-feather sleeping bag which kept me warm at night.
On one trip we went to Idlehour Campground via the Henninger Flats and the Idlehour Trail. Leaving our gear at Idlehour, we hiked up the canyon to the cabins in Deer Park. There was some kind of a unlocked gate and sign at the start of the branch trail to the cabins, saying something like "Private Cabins" implying that we shouldn't go there, but we did anyway. Then from in back of these cabins we started hiking off-trail up the slope and eventually reached Mt. Wilson very late in the day. Neither of us had a flashlight. But we ran down the dirt Mt. Wilson Toll Road and managed to get back to Idlehour Campground just as it was getting too dark to safely travel.
On the other trip we hiked the stretch of the trail-less tributary between the confluence of it with Eaton Canyon (a short ways below Idlehour Campground and)and the point where the Idlehour Trail fords the stream of this tributary on its way to Mt. Lowe. We talked to a couple of other boys who were camped there at the tributary, although there wasn't a campground there. There were some minor waterfalls to climb around in the trial-less tributary.
On these trips we went between Sugar Bowl and Idlehour 2 ways: via the fine trail high above the E side of the stream and via the canyon bottom. I remember seeing at least one a car parked in the "parking lot" ("Telephone Flat" per Brennen).
On the way down to Altadena on one of these 2 backpacking trips, we went down the ridge that is above Henninger Flats, almost all the way to Altadena. As the ridge route nears the Eaton Canyon bridge (near the start of the Mt. Wilson Toll Road) it's necessary to descend to the road prior to reaching the bridge at a location which in the future had rock slides which covered the road. We managed to select a route to go down that turned out to be easier than it looked. Road repairs since then have made some of this slope almost vertical and it's not clear if one can still use this ridge route today.
Since neither of us had a car, we likely got one of our parents to drive us to the start of the backpacking trips and upon returning, took buses home, one of which we had to had to walk down to New York Drive to catch.