Question: In which European mountain range will you find the mountains Grassen and Titlis both found between the cantons of Obwalden and Berne?
Context: The Elkhead Mountains are a mountain range in Colorado.  The mountain range is considered to be low altitude within Colorado as the mountains are under 11000 ft .  Located within Routt and Moffat counties, the mountain range is far from metropolitan areas and has few lakes and streams, so it attracts few visitors.  The mountain range is a volcanic range and all of the peaks were formed by volcanic action.  The mountain range extends approximately 16 mi east to west and 10 mi north to south, and its center is located at , approximately 20 mi northeast of Craig and north of Hayden, Colorado 13 mi south of the Wyoming border.  Almost all of the peaks within the Elkhead Mountains are a part of Routt National Forest.  Significant peaks are: Bears Ears, Sugar Loaf, Saddle Mountain, Black Mountain, Pilot Knob, and Meaden Peak. The Grassengrat is a multi-summited mountain of the Urner Alps, located on the border between the cantons of Obwalden and Uri in Central Switzerland.  It lies on the range between the Titlis and the Gross Spannort.  The main summit has an elevation of 2,941 metres and is named "Stössenstock". The Grassen is a mountain of the Urner Alps, located east of the Titlis in Central Switzerland.  The summit is the tripoint between the cantons of Berne, Obwalden and Uri. The Krucze Mountains (Czech: "Vraní hory" , German: "Rabengebirge" Polish: "Góry Krucze" ) are the Eastern part of the Stone Mountains, which belong to the Central Sudetes on the border of the Czech Republic and Poland.  To the West and North-Western part the mountain range borders the Lubawska Plateau and the Karkonosze Mountains, to the North-Eastern part they border the mountain range Czarny Las, from the East they border the sediment basin Kotlina Krzeszowska and the Zawory mountain range and to the South the mountain range borders the Czech part of the Stołowe Mountains.  To the Southern ridge of mountain range is the Polish-Czech border.  The border crossing for cars is in Lubawka and for tourists is in Okrzeszyn. Titlis is a mountain of the Uri Alps, located on the border between the cantons of Obwalden and Berne.  At 3238 m above sea level, it is the highest summit of the range north of the Susten Pass, between the Bernese Oberland and Central Switzerland.  It is mainly accessed from Engelberg (Obwalden) on the north side and is famous as the site of the world's first rotating cable car.  The cable car system connects Engelberg (996 m ) to the summit of "Klein Titlis" (3028 m ) through the three stages of "Gerschnialp" (1262 m ), "Trübsee" (1796 m ) and "Stand" (2428 m ). The Reissend Nollen is a mountain peak of the Urner Alps, located on the border between the Swiss cantons of Obwalden and Bern.  It lies on the range west of the Titlis, between Engelberg and Gadmen. The Emmental Alps (German: "Emmentaler Alpen" ) are a mountain range in the western part of the Alps, in Switzerland.  They are located north-west of the Brünig Pass, mainly in the cantons of Lucerne, Bern, and Obwalden, with a small portion in the canton of Nidwalden.  The highest summit of the range is the Brienzer Rothorn, which is also the highest point in the canton of Lucerne.  The range is named after the Emme valley (German: Emmental).  In the north-west corner one finds the relatively low, but widespread, and very furrowed Napf. The term alpine refers to the Alps, a European mountain range, or to the Alpine states associated with the mountain range. This is a list of mountains of the Swiss canton of Obwalden.  Obwalden is a very mountainous canton and is one of the nine cantons having summits over 3,000 metres.  Topographically, the three most important summits of the canton are those of the Titlis (most elevated), the Brienzer Rothorn (most prominent) and Pilatus (most isolated). Qaflankuh or Qaflankuh Mountain Range (Persian: رشته کوه‌ها‌ی قافلانکوه / Reshteh Kuh-hā-ye Qāflānkuh) is a mountain range that is located about 20 kilometres north of the city of Zanjan in Zanjan Province, Iran.  With an average width of almost 20 kilometres and a length of about 100 kilometres, this mountain range is stretched in a northwest-southeast direction, beginning from northwest of Zanjan, passing north of Zanjan and ending southeast of Zanjan.  The Qezel Owzan River flows in a valley that separates Qaflankuh Mountains on the south from Talish Mountains on the north.  With an elevation of 2971 metres, Mount Sendan Dagh is the highest mountain of the range which is located in the southeast section of this mountain range.  There are some mineral hot springs containing sulphur in different parts of this range.  Geologically, Qaflankuh Mountain Range was formed during the Tertiary volcanism and plutonism and is made mainly of the Eocene volcanic rocks with very small sections of intrusive rocks in the northern and southern parts of the range.
Answer: Alps