Ypsilon Mountain- Blitzen Ridge with Aces

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July 26, 2026

The East Ridge of Ypsilon Mountain (more often referred to as Blitzen Ridge) is a very popular alpine scramble route in the northern part of Rocky Mountain National Park. In the middle of this ridge are four large fins of rock called the Four Aces. While the standard Blitzen Ridge route bypasses three of the Aces to their south, a more interesting variation summits all of them, remaining more or less on the very crest of the ridge except for a short bit after Second Ace. 

Routes climbed

Name	Grade (YDS)	# Pitches	Quality (1-5)	Type
Blitzen Ridge (variation: summiting Four Aces)	5.8	N/A	4	trad

Peaks/Towers climbed

Peak	Elevation	Topographic Prominence	Summit Coordinates (lat/lon)
First Ace	12,038 ft	40 ft	40.45304, -105.67195
Second Ace	12,119 ft	100 ft	40.45347, -105.67245
Third Ace	12,219 ft	100 ft	40.45383, -105.67291
Fourth Ace	12,227 ft	110 ft	40.45431, -105.67377
Ypsilon Mountain	13,511 ft	1,159 ft	40.45708, -105.68117

Gear

- 30m rope
- cams: single 0.2-2
- small-medium nuts
- 8 alpine draws

Total Stats

12.2 miles

5,400 ft gain/loss

Mike and I started from Lawn Lake Trailhead just before 4am, taking the well maintained Ypsilon Lake Trail for about 4.4 miles to Ypsilon Lake. This trail dead ended on the west side of the lake, and we began cross country travel here around to the north side of the lake with a short section of bushwhacking. We continued north up a gully to access the eastern toe of Blitzen Ridge. Here the going was easy with nothing more than light rock hopping. 

We continued up the ridge as it narrowed and grew increasingly blocky. Soon we could see the Aces which marked an abrupt change in terrain from mellow to technical.

First Ace was very straightforward. It was easy to go up and over it on class 3 terrain by staying slightly left of its Southeast Ridge. This was the smallest Ace. 

From the First-Second Ace Notch, we roped up and climbed a pitch up the South Face, just left of Second Ace's South Ridge. This went at about 5.6 and was a little loose. We reversed back down the pitch afterwards. 

South Face route (up and down) of Second Ace

After packing up the rope, we skirted around the left side of Second Ace, briefly following the standard route. 

At the Second Ace-Third Ace saddle, we briefly considered getting out the rope but didn't. Third Ace's South Ridge (class 5.4) was short and sweet. A small dihedral near the top marked the crux.

ascending Third Ace

summit of Third Ace

The downclimb of the opposite ridge down Third Ace was highly enjoyable with solid rock and knife edges. We pretty much stayed directly on the ridge here. Shame it was so short. 

The standard route bypasses Fourth Ace to the right, skirting around it on a series of slabs and flakes (class 5.4). Instead we climbed a direct route up its southeast ridge. I found really great rock and secure climbing. To top it off, there was a cool little mini hand crack rooflet towards the right just below the summit (5.8-ish). There might've been an easier way around to the left, but the rooflet looked like great fun so I went for it. I belayed Mike up to the summit and we put the rope and gear away. 

halfway up Fourth Ace

view from the summit of Fourth Ace, with a party descending Third Ace

Descending Fourth Ace's Northwest Ridge was short and easy (class 3). We were now finished with the Aces, but a good chunk of Blitzen Ridge was still ahead. We scrambled up some easy terrain to a short distinct band of white rock which went at low 5th. After climbing over this, we briefly dropped and contoured along the left side of the ridge, then headed back right onto the crest. From there the ridge was easy as we ascended another 1,000 ft of elevation on class 2 terrain to the summit of Ypsilon. 

looking northwest from Fourth Ace

through the white band

continuing up the easy part of the ridge

marmot just below summit

summit of Ypsilon Mountain

There were several other groups on the summit of Ypsilon as we arrived, all of which had hiked over from Fall River Pass. There were several puffy white clouds building quickly in the sky now, so we didn't stay for long as it was a matter of time before lightning started. 

From the summit we descended south down a plateau for a few minutes before veering southeast down a steeper ridge which bordered the southern side of Spectacle Lakes. This was the standard descent for Blitzen Ridge. We followed this ridge all the way down to the eastern Spectacle Lake. At 12,300 ft there was a class 4 step of rock which looked like it wouldn't go until we were downclimbing it.

downclimbing the class 4 step

From eastern Spectacle Lake we headed down the westernmost of two drainages that descended steeply south, finding a nice use-trail with gradually became more defined. As we descended into a east-west-running valley to the south, the trail hooked east along a creek to Ypsilon Lake. We rejoined our earlier trail at Ypsilon Lake as thunder rumbled and heavy drops of rain poured through the trees. There were several people backpacking up as we descended the Ypsilon Lake Trail, not really minding the rain which soon turned into a steady drizzle and was quite pleasant in the afternoon warmth. We made it back to Lawn Lake Trailhead sometime in early/mid afternoon.