Total population (1990 census): 86403
County seat: Dubuque
Crop Statistics (1997 US Census of Agriculture)
| Cereals | Farms | Acres | Yield | |
| Maize=Corn | 1105 | 116149 | 15465826 bu | |
| Wheat for Grain, Total | 8 | 89 | 2590 bu | |
| Barley | 25 | 446 | 24674 bu | |
| Oats | 486 | 10651 | 684767 bu | |
| Popcorn | 4 | 24 | 59200 lbs, shelled | |
| Rye | 3 | 70 | D | |
| Grain Legumes | Farms | Acres | Yield | |
| Soybean | 269 | 19886 | 978026 bu | |
| Forages | Farms | Acres | Yield | |
| Total Hay* | 1021 | 67863 | 222645 tons, dry | |
| Alfalfa Hay | 953 | 47487 | 172185 tons, dry | |
| Small Grain Hay | 136 | 2463 | 5407 tons, dry | |
| Tame Hay | 64 | 1439 | 3735 tons, dry | |
| Wild Hay | 6 | D | 740 tons dry | |
| Grass Silage | 294 | D | 121722 tons, grn | |
| Corn for Silage | 391 | 9797 | 162307 tons, grn | |
| Vegetables | Farms | Acres | Yield | |
| Asparagus | 4 | 3 | ||
| Snap Bean | 9 | 10 | ||
| Green Onions | 3 | 1 | ||
| Sweet Peppers | 3 | 2 | ||
| Pumpkins | 4 | D | ||
| Sweet Corn | 3 | D | ||
| Tomatoes | 6 | 3 | ||
| Fruits | Farms | Acres | Yield | |
| Apples | 17 | 92 | 6708 trees | |
| Grapes | 11 | 5 | 2250 vines | |
| Peaches | 3 | D | D | |
| Raspberries | 3 | 1 | 1070 lbs | |
| Strawberries | 4 | 3 | D | |
| Nursery and Greenhouse Crops, Cut Christmas Trees Harvested, Mushrooms, and Sod Grown for Sale | Farms | Sq. ft. under glass or other protection | Acres in the open | Sales ($1,000) |
| Nursery and Greenhouse Crops | 18 | 64453 | 48 | 374 |
| Florculture Crops | 6 | 54673 | D | 161 |
| Bedding/Garden Plants | 6 | 54673 | D | 161 |
| Cut Christmas Trees Harvested | 4 | X | 8 | D |
| Nursery Crops | 7 | D | 31 | 86 |
| Other Nursery and Greenhouse Crops | 4 | D | D | 40 |
*Alfalfa, grass silage, green chops etc.
D=Withheld to avoid disclosing data for individual farms.
X=Not applicable.