A gas trap system, comprising: a motor; a gas trap configured to agitate drilling fluids when positioned in a return tank, and then to release gases during agitation, the gas trap comprising: an elongated canister having a wall, a through-opening at a lower end of the canister configured to receive drilling fluids from the return tank, an impeller adjacent the lower end of the canister, a shaft residing axially along the canister, with the shaft operatively connected to the impeller and configured to impart rotational movement to the impeller in response to energy provided by the motor, thereby agitating the drilling fluids within the canister, a liquids exhaust port along the wall of the canister configured to release liquids from the canister during fluid agitation, and a gas exhaust port configured to release gases from a top end of the canister also during fluid agitation; at least one vertical guide rod; an upper guide rod plate having through openings for slidably receiving and securing corresponding vertical guide rods; a guide stand comprising: an elongated vertical bar having an upper end and a lower end, the lower end being releasably connectible to the return tank, and an extension tubing having a first end and a second end, wherein the first end is operatively connected to the vertical bar intermediate the upper and lower ends of the vertical bar, and the second end is operatively connected to the upper guide rod plate; wherein the upper guide rod plate serves as an upper travel limit to the gas trap as the gas trap floats along the vertical guide rods in response to changes in a characteristic of the drilling fluids. a motor; a gas trap configured to agitate drilling fluids when positioned in a return tank, and then to release gases during agitation, the gas trap comprising: an elongated canister having a wall, a through-opening at a lower end of the canister configured to receive drilling fluids from the return tank, an impeller adjacent the lower end of the canister, a shaft residing axially along the canister, with the shaft operatively connected to the impeller and configured to impart rotational movement to the impeller in response to energy provided by the motor, thereby agitating the drilling fluids within the canister, a liquids exhaust port along the wall of the canister configured to release liquids from the canister during fluid agitation, and a gas exhaust port configured to release gases from a top end of the canister also during fluid agitation; an elongated canister having a wall, a through-opening at a lower end of the canister configured to receive drilling fluids from the return tank, an impeller adjacent the lower end of the canister, a shaft residing axially along the canister, with the shaft operatively connected to the impeller and configured to impart rotational movement to the impeller in response to energy provided by the motor, thereby agitating the drilling fluids within the canister, a liquids exhaust port along the wall of the canister configured to release liquids from the canister during fluid agitation, and a gas exhaust port configured to release gases from a top end of the canister also during fluid agitation; at least one vertical guide rod; an upper guide rod plate having through openings for slidably receiving and securing corresponding vertical guide rods; a guide stand comprising: an elongated vertical bar having an upper end and a lower end, the lower end being releasably connectible to the return tank, and an extension tubing having a first end and a second end, wherein the first end is operatively connected to the vertical bar intermediate the upper and lower ends of the vertical bar, and the second end is operatively connected to the upper guide rod plate; an elongated vertical bar having an upper end and a lower end, the lower end being releasably connectible to the return tank, and an extension tubing having a first end and a second end, wherein the first end is operatively connected to the vertical bar intermediate the upper and lower ends of the vertical bar, and the second end is operatively connected to the upper guide rod plate; wherein the upper guide rod plate serves as an upper travel limit to the gas trap as the gas trap floats along the vertical guide rods in response to changes in a characteristic of the drilling fluids.