That's not a whale. It's a submarine!
Overview: The Coconino National Forest is one of the most diverse National Forests in the country with landscapes ranging from the famous Red Rocks of Sedona to Ponderosa Pine Forests, to alpine tundra. Explore mountains and canyons, fish forest lakes and wade in lazy creeks and streams. The Red Rock district, centered on the town of Sedona, encompasses many of the famous red rock buttes and mesas, and canyons that have made Sedona famous as a resort town. Just north of Sedona is Oak Creek Canyon, one of the many large canyons located along the Mogollon Rim. Oak Creek Canyon is one of the most popular recreation destinations in the Coconino National Forest and along with Sedona is Arizona's second most popular tourist attraction, second only to the Grand Canyon.
The parking area for the trailhead can be found at the end Morgan Road. The parking area is accessed via a short dirt and gravel road. Parking is limited and there are "No Parking" signs on Morgan Road around the area where it becomes the dirt access road. In addition to the Broken Arrow Trail (which is used to access Submarine Rock), the Margs Draw Trail can be accessed as well. The Broken Arrow Trail leads to the Chapel and Little Horse Trails. The Margs Draw Trail leads to the Munds Wagon and Huckaby Trails. There are no amenities at the trailhead area other than informational kiosks and a registration notebook (in particular, no water nor restrooms).
For pre- or post-hike activities, the closest venues are in the Tlaquepaque area (less than 2 miles north), Uptown Sedona (a bit more than 2 miles north), West Sedona (4 miles north and west), and the Village of Oak Creek (6 miles to the south).
To get to the trailhead from the Village of Oak Creek, head north on AZ-179 about six miles or less to the Morgan Road roundabout. Take Morgan Road to the right (east) for about one-half mile to the dirt road. Take the dirt road in and to the right. The first parking spots are about 450 feet in from the paved road with more parking further in.
Warning: Read and heed the warning below.
Hike: This description is of an "out and back" hike. This description breaks the outbound portion (the same as the inbound portion) into three components: the Broken Arrow trail to the fork, from the fork to emergence onto the rock, and a short component focused on the rock itself.
The initial leg of this hike is coincident with the first 0.98 mile of the Broken Arrow Trail (#125). As you drive into the main parking area, you'll see the Broken Arrow Road/Coconino National Forest sign. This sign notes that this area is "MANAGED IN COOPERATION WITH PINK JEEP TOURS." The association with Pink Jeep Tours provides for some interesting diversions on the trail as, at several points, you may be able to watch a jeep climbing up or wobbling down a fairly steep 4X4 trail, to the amusement/terror of the tourist occupants. Near the start of the trail, you'll see a metal sign with "TRAIL 125/BROKEN ARROW" cut through the plate. Nearby, you'll see the regional Forest Service informational map with the obligatory "You Are Here" arrow on the smaller schematic map to the right. You notice that the schematic map reminds you to "Please follow the Cairns!" After diligently studying the maps, follow the trail 0.05 mile to the registration book on the left. Of course, it's a good idea to sign-in. As you walk along the trail, about 0.10 mile later, you'll see one of the only fancy plastic "National Forest Trail" markers. Just beyond that marker is a cairn, one of many you'll see on this trail. A short 0.11 mile later, you'll be in a good position to see (to your left) the markings left on a stone trail by the rubber tires of 4X4 vehicles. The trail then proceeds roughly south for 0.25 mile and then hooks east and eventually down for 0.16 mile. At the bottom of the incline, you'll have an opportunity to leave the trail and take a detour to the left to look into the Devil's Dining Room. The Devil's Dining Room is a sinkhole 25 to 30 feet wide and 90 or more feet deep. The mouth of the sinkhole has been surrounded by a barbed wire fence for the safety of visitors. It is believed that the sinkhole is a major underground roost for bats. Proceeding south again, then east, for a total of 0.33 mile, gets you to what I call "The Fork," where you can go to the right to proceed to Chicken Point or veer to the left to head off to Submarine Rock.
Of course, we take the left tine to go to Submarine Rock (all told, a 0.88 mile hike from this point). About 0.12 mile later, you find yourself on one of the several wide stone expanses where the red rock that underlies all of the soil in these parts is exposed. Obviously, this is a great place to stop for some yoga, so that's what you do. After accomplishing the crane pose (bakasana) and the dancer's pose (natarajasana), you continue with the hike. After 0.19 mile (during which you head east then arc out and down) you come to a point where you can see Submarine Rock in all its glory. After you cross a 4X4 trail and 0.02 mile later, you see a cairn with a sign sticking out of it telling you that Submarine Rock is ahead. You proceed northeast to the base of the rock then out a ways into the forest then back to the base of the rock. At that point, after traveling about 0.21 mile from the cairn/sign, as you're walking across bare rock, if you look up and to the right, you'll see a more direct path to the northern prominence of Submarine Rock. I'd imagine folks have taken that route to the top, but it's advisable to continue forward on the trail to take the "safer" route. Just 0.11 mile later, you have a great view of the huge rock outcropping that prominences at (34.833236, -111.744362). A short 0.05 mile later, you emerge from the forest onto the base of Submarine Rock.
From the base, it's a fast 0.04 mile to the "top" of the southern prominence of Submarine Rock. Looking northwest, you will see the northern prominence of Submarine Rock (and likely some people taking in the view from that local high point). You can get to the base of the northern prominence by walking about 0.12 mile northwest across Submarine Rock. (Note: the following is provided for informational purposes only. I am in no way suggesting that you go to the northern prominence. Any action taken is at your own risk.) From this point, there are a number of ways to mount the northern prominence, but one of the easier ways is by making your way up the lip below the prominence a little west and to the left of a split in that lip. Hop across that split and follow it to the right a bit until you come to a reasonable grade up which you can pop to the top. From this vantage point, you can look southeast to the southern prominence. Perhaps you'll see someone taking a picture of you and you can take a picture of them, too. Of course, you'll also be treated to excellent views of Sedona and beyond and of the red rocks area all around you. Dismounting is accomplished by using a slightly different path. Rather than going back the way you came up, proceed down a bit beyond the lip and look for an place to the right/east of the split in the lip where you can easily slide down into the little crevasse. My track contains hints on how to accomplish both the mounting and dismounting of the northern prominence.
This description makes use of material from the Coconino forest service, Wikipedia, FS - Trails, and FS - #125.
WARNING! Hiking and outdoor related sports can be dangerous. Be responsible and prepare for the trip. Study the area you are entering and plan accordingly. Dress for the current and unexpected weather changes. Take plenty of water. Never go alone. Make an itinerary with your plan(s), route(s), destination(s) and expected return time. Give your itinerary to trusted family and/or friends.