C.R.S. § 18-4-105

(1) A person who knowingly or recklessly starts or maintains a fire or causes an explosion, on his own property or that of another, and by so doing places another in danger of death or serious bodily injury or places any building or occupied structure of another in danger of damage commits fourth degree arson.

(2) Fourth degree arson is a class 4 felony if a person is thus endangered.

(3) Fourth degree arson is:

(a) A petty offense if only property is thus endangered and the value of the property is less than three hundred dollars;

(b) A class 2 misdemeanor if only property is thus endangered and the value of the property is three hundred dollars or more but less than one thousand dollars;

(c) A class 1 misdemeanor if only property is thus endangered and the value of the property is one thousand dollars or more but less than two thousand dollars;

(d) A class 6 felony if only property is thus endangered and the value of the property is two thousand dollars or more but less than five thousand dollars;

(e) A class 5 felony if only property is thus endangered and the value of the property is five thousand dollars or more but less than twenty thousand dollars;

(f) A class 4 felony if only property is thus endangered and the value of the property is twenty thousand dollars or more but less than one hundred thousand dollars;

(g) A class 3 felony if only property is thus endangered and the value of the property is one hundred thousand dollars or more but less than one million dollars; and

(h) A class 2 felony if only property is thus endangered and the value of the property is one million dollars or more.

(4) Repealed.

(5) It shall not be an arson offense pursuant to this section if:

(a) A person starts and maintains a fire as a controlled agricultural burn in a reasonably cautious manner; and

(b) No person suffers any of the following as a result of the fire:

(I) Bodily injury;

(II) Serious bodily injury; or

(III) Death.

(6) For purposes of this section, "controlled agricultural burn" means a technique used in farming to clear the land of any existing crop residue, kill weeds and weed seeds, or reduce fuel buildup and decrease the likelihood of a future fire.