This is a fun little climb to get your heart pumping, starting at a popular trailhead. It is about 11 miles round trip if you don't take any wrong turns. In the winter it is an excellent ski route, on a snowy ridge above the trees, and at least three miles of snow covered trails below. In fact, the mountain may be more popular in the winter.
On a topo map, this route looked like the most obvious and easiest route to the summit, although CharlesD had documented the other two. Except for a few wrong turns, we followed the route described below, and it was
Approach (Heart Lake)
First look at Heartbeat Peak
Start at the South Boulder Creek Trailhead at the east portal of the Moffat Tunnel. The trailhead is 8 miles west of Rollinsville at the end of a good dirt road. There is a large parking lot at the tunnel. Follow the South Boulder Creek Trail. At 2.7 miles the creek forks. Take the right fork, toward Heart Lake. If the trail is snow-covered, you will likely miss this fork and continue toward Rogers Pass Lake. Don't worry, once you come out of the trees you can tell where you are, and you will be able to adjust course and get back to Heart Lake. By the most direct route, it is 4 miles to Heart Lake.
Showing part of the East Ridge route
Hike north along the east end of Heart Lake, up a rocky slope, until you reach the crest of a broad ridge. This is Heartbeat Peak's east ridge, and you will follow it right to the summit. Stay to the north (right) side of the ridge early on to keep the climbing difficulty to a minimum. In winter, there are two short, steep snow pitches just below the summit. If the snow is powdery and deep, this will be the most difficult portion of your climb.
On the descent, retrace your steps. You may be tempted to shortcut straight down into the creek drainage because you know the main trail is down there. However, from there you cannot see the steep dropoff awaiting you at the end of the ridge.
Standard day hiking gear in summer. Be prepared for full alpine conditions in the winter, although you may experience mild weather.