All of the Swan Valley [1] is lovely, but perhaps no single spot captures the essence of this narrow, lake-filled valley flanked by sawtooth peaks as well as Holland Lake.
In addition, the lake is graced with a charming old-fashioned resort [2] that has played home to generations of visitors.
Links:
[1] http://www.moon.com/destinations/montana/missoula-and-northwestern-montana/the-swan-and-blackfoot-valleys
[2] http://www.moon.com/destinations/montana/missoula-and-northwestern-montana/the-swan-and-blackfoot-valleys/holland-lake-and-c/accommodations