Here is the full list of all 22 The Montana Chronicles: Montana's Croatoa achievements.
Complete Clay Shaft: 5-E
Complete Clay Shaft: 4-E
Complete Clay Shaft: 3-E
Complete Clay Shaft: 2-E
Complete Clay Shaft:1-E
Complete Clay Shaft: 5-D
Complete Clay Shaft: 4-D
Complete Clay Shaft: 3-D
Complete Clay Shaft: 2-D
Complete Clay Shaft: 1-D
Complete Clay Shaft: 5-C
Complete Clay Shaft: 4-C
Complete Clay Shaft: 3-C
Complete Clay Shaft: 2-C
Complete Clay Shaft: 1-C
Complete Clay Shaft: 5-B
Complete Clay Shaft: 4-B
Complete Clay Shaft: 3-B
Complete Clay Shaft: 2-B
Complete Clay Shaft: 1-B
Complete Clay Shaft: 5-A
Complete Clay Shaft: 4-A