Take Exit 221 at Bakerville on Interstate 70 and continue to the south side of the highway and the start of Forest Road 189 (goes to the Grays Peak Trailhead). Start up the 189 road and after over a mile, turn right on the Grizzly Gulch road. It is a rough, narrow 4WD road so park along the first 1/4 mile if don't have jeep or other small, high-clearance vehicle. To continue higher, stay right on the "189.1c" road after 1/4 mile and continue west into Grizzly Gulch.
The "Tuning Fork" is one of the longest snow routes on a Colorado 14er - Photo #1 and Photo #2. In spring, it can provide 3,000' of continuous snow, maybe even from the summit. Lou Dawson refers to it as the "Big-ol-strip-o-snow" in Colorado's Fourteeners Volume 1 The Northern Peaks. Follow the Grays Peak road (#189) over a mile to the Grizzly Gulch road junction. Turn right and continue 1/4 to reach some buildings up to the left. Stay right on the "189.1c" road and continue for approximately 1 mile to a stream crossing and then another mile to a clearing near 11,200' where you can see the route off to your left (south) - Photo #3 and Photo #4.
Drop down a bit to the center of the gulch and hike south (Photo #4) to reach a semi-steep slope that blocks the base of the main couloir. The easiest terrain is on the right (west) side of the slope. Climb the slope and angle toward the bottom of the couloir - Photo #5 and Photo #6. Crampons and axe are recommended beyond this point. Also, this is a good place to make a decision on the safety of the snowpack above. You are immediately faced with some moderately-steep snow and it's a bad place to be if the snow above is at high risk of avalanche. Start climbing. Depending on the stability of the snow, you may want to stay out of the couloir's fall-line by climbing up the right (west) side of the snow. After a few hundred feet, the pitch eases a bit and you will get a sense of how long this snow climb really is. Photo #7 looks down the lower couloir.
Continue climbing the main couloir to approximately 12,400' where the "fork" comes into view - Photo #8. The fork is a split where another couloir starts up to the east of the main couloir. Continuing up to 12,500' provides a more distinct view of the fork - Photo #9 and Photo #10. Now, you have two general options: 1) Continue up the main (west) couloir, or 2) turn left and climb the east couloir. The east couloir is slightly less steep and ends just below the summit. The west one goes straight up to the west ridge and allows you to hike up the ridge a few hundred feet instead of the loose rock above the east couloir. There's no huge advantage to either option, so I'll break them down separately:
Ascending the main (right) couloir:
Stay right at the junction and continue up the main couloir. Photo #11 looks over at the junction from 12,700'. The main couloir has several areas where rocks may be poking out of the snow. Continue up steeper snow between 12,800' and 13,000' - Photo #12, Photo #13 and Photo #14. Staying on the right side of the couloir may be helpful, but this will lead you to some rock patches that may force you back towards the center of the couloir. Photo #15, Photo #16 and Photo #17 show the terrain below 13,300'.
Above 13,500', the top of the couloir becomes more defined and it's not difficult to identify the easiest way to the ridge above - Photo #18. Continue to the top of the couloir and possibly the end of the snow - Photo #19. Photo #20 looks down from this area. Follow the path of least resistance above the couloir and toward the ridge, which you can't really see until you are near 14,000'. Climb (Difficult Class 2) up through the rocky terrain to reach the crest of the west ridge, near 14,100'. Turn left (east) and hike 0.1 mile to the summit - Photo #21. If you take a few steps north off of the summit, you can see portions of the route below - Photo #22. Don't forget to take in the views - Photo #23.
Ascending the east (left) couloir:
Some may find the east couloir a more-direct climb to the summit. At the couloir junction (Photo #24) turn left and climb up through a "choke" of rocks (Photo #25) that block easy access to the couloir. When there's a lot of snow, there may be a couple of ways to pass through this area. Generally, Photo #24 shows the easiest passage. After passing through the "choke" (Photo #26), continue up the obvious couloir - Photo #27. The climbing may seem a bit more straightforward than the west couloir. As you gradually gain elevation ,don't forget to look down to see how much you really have gained to this point - Photo #28 and Photo #29.
As you approach 13,800', the snow may run out on you and you'll have to make a decision on which line to take to the summit - Photo #30. Photo #31 snows the terrain that's hard to see from your current position. Usually, the best option is to continue left (east) up a snow spur at the top of the couloir. That spur (upper left line drawn on Photo #31) leads to rocky, Class 2 terrain just below the summit. Taken from just west of that spur, Photo #32 looks east across the terrain below the summit. Another option is to climb Difficult Class 2 terrain through rocks above the right side of this couloir (the dotted line in Photo #31). This option is steeper but may have more snow just below the ridge crest. Pick your line and continue up to the summit. Taken from just below the summit, Photo #33 looks down on the upper route.
This route provides one of the longest 14er skis in the state. In fact, you could ski all the way back to I-70 without much trouble. That's 4,500' of elevation. In spring, the terrain just below the summit tends to be snow-free or provide limited continuous snow into the couloirs that make up the tuning fork. If this is the case, look for continuous snow between the rocks above the dotted line in Photo #31. Even if you have to descend a bit to reach the snow, two very long snow-filled couloirs await. Photo #27 and Photo #28 were taken on a powder ski day.
Snowmobilers ride on the Grizzly Gulch road, but don't bet on it. It's a narrow road and, without a sled track, it can be hard to follow through the forest. A GPS with pre-loaded waypoints may be quite helpful.