This is from the Wyoming Game and Fish Department site about legal archery equipment.
"ARCHERY. Longbows to be used for antelope, bighorn sheep, black bear, deer, mountain goat or mountain lions must have at least 40 lbs. draw weight or be able to shoot a 400 grain arrow at least 160 yards. For elk or moose, the longbow must have at least 50 lbs. draw weight or be able to shoot a 500 grain arrow at least 160 yards. Crossbows must have at least 90 lbs. draw weight, a minimum draw length of 14 inches from front of bow to back of string in the cocked position, a positive safety mechanism, and must be cocked by hand without leverage-gaining devices. The Commission, by regulation, may authorize a physically handicapped person to use a leverage-gaining device for cocking a crossbow. Crossbow bolts must be at least 16 inches. The broadhead of arrows or bolts shall be sharp steel with a minimum cutting width of one inch." (My bolded emphasis.)
I believe some states have a cutting edge length requirement while others have a cutting width requirement.