Fields (montana Map):

You begin with fields 3 and 39, and you can buy the rest. To get the Farmland Tycoon achievement, you'll need to buy every field in Montana. Using the in-game info, size is the size in acreage, best crop is the type, not the specific crop (so grain or root, not wheat or potatoes), and optimal income is per acre. So, field #2 has an optimal income of $5,915 per acre and is 3 acres, $17,745 is the optimal total income.

Field #1
Price: $7,500
Size: 3
Best crop: Grain
Optimal income: $5,915

Field #2
Price: $7,500
Size: 3
Best crop: Grain
Optimal income: $5,915

Field #3
Price: Free
Size: 2

Field #4
Price: $7,00
Size: 2
Best crop: Root
Optimal income: $5,323

Field #5
Price: $7,000
Size: 2
Best crop: Grain
Optimal income: $5,323

Field #6
Price: $16,000
Size: 4
Best crop: Grain
Optimal income: $5,915

Field #7
Price: $58,200
Size: 12
Best crop: Grain
Optimal income: $5,323

Field #8
Price: $53,100
Size: 12
Best crop: Root
Optimal income: $4,436

Field #9
Price: $7,000
Size: 2
Best crop: Grain
Optimal income: $5,323

Field #10
Price: $33,600
Size: 7
Best crop: Grain
Optimal income: $3,549

Field #11
Price: $26,550
Size: 7
Best crop: Grain
Optimal income: $4,436

Field #12
Price: $7,500
Size: 2
Best crop: Root
Optimal income: $5,915

Field #13
Price: $58,200
Size: 14
Best crop: Root
Optimal income: $5,323

Field #14
Price: $35,400
Size: 9
Best crop: Grain
Optimal income: $4,436

Field #15
Price: $60,000
Size: 9
Best crop: Grain
Optimal income: $5,915

Field #16
Price: $49,000
Size: 10
Best crop: Grain
Optimal income: $5,323

Field #17
Price: $5,000
Size: 5
Best crop: Grain
Optimal income: $2,957

Field #18
Price: $97,000
Size: 21
Best crop: Grain
Optimal income: $5,323

Field #19
Price: $5,000
Size: 2
Best crop: Root
Optimal income: $2,957

Field #20
Price: $7,780
Size: 4
Best crop: Grain
Optimal income: $2,366

Field #21
Price: $38,800
Size: 8
Best crop: Grain
Optimal income: $5,323

Field #22
Price: $17,700
Size: 5
Best crop: Root
Optimal income: $4,436

Field #23
Price: $20,000
Size: 5
Best crop: Grain
Optimal income: $5,915

Field #24
Price: $67,200
Size: 15
Best crop: Grain
Optimal income: $3,549

Field #25
Price: $12,500
Size: 7
Best crop: Root
Optimal income: $2,366

Field #26
Price: $31,200
Size: 13
Best crop: Grain
Optimal income: $2,366

Field #27
Price: $50,400
Size: 14
Best crop: Root
Optimal income: $3,549

Field #28
Price: $60,000
Size: 12
Best crop: Grain
Optimal income: $5,915

Field #29
Price: $116,400
Size: 19
Best crop: Grain
Optimal income: $5,323

Field #30
Price: $88,500
Size: 13
Best crop: Grain
Optimal income: $4,436

Field #31
Price: $155,200
Size: 36
Best crop: Root
Optimal income: $5,323

Field #32
Price: $300,000
Size: 61
Best crop: Grain
Optimal income: $5,915

Field #33
Price: $339,500
Size: 9
Best crop: Grain
Optimal income: $5,915

Field #34
Price: $132,750
Size: 31
Best crop: Root
Optimal income: $4,436

Field #35
Price: $77,600
Size: 7
Best crop: Grain
Optimal income: $5,323

Field #36
Price: $30,000
Size: 7
Best crop: Grain
Optimal income: $5,915

Field #37
Price: $13,000
Size: 3
Best crop: Root
Optimal income: $5,915

Field #38
Price: $25,200
Size: 7
Best crop: Root
Optimal income: $3,549

Field #39
Price: Free
Size: 4

Field #40
Price: $53,100
Size: 12
Best crop: Grain
Optimal income: $4,436

Field #41
Price: $310,400
Size: 42
Best crop: Grain
Optimal income: $5,323