This is Odessa Lake, yet another beautiful alpine lake located in Rocky Mountain National Park. The trail to this lake is a strenuous 4.5 mile hike from the Bear Lake area, followed by another 4.75 miles to the Fern Lake area where you can catch a bus back to the Bear Lake parking lot.
The entire trail is gorgeous and well worth the effort. I highly recommend this trail if you can manage the distance. If you do go for it know that the first 2.9 miles to Lake Helene will be the most difficult and then it is mostly down hill, all the way to the Fern Lake parking area.