I really hope you are trolling.
if not, Groudon cannot be found in gold version. or silver version. Groudon was introduced in ruby and sapphire
You get Groudon in Pokemon Heart Gold by trading with somebody who's found Groudon in Soul Silver. You can't find Groudon in Heart Gold, you find Kyogre. Soul Silver players find Groudon.
Groudon isn't in HeartGold, it is in SoulSilver. Kyogre is in HeartGold as well as Rayquaza.
if you have action replay you will get to pick a pokemon so groudon is a hard pokemon you need the red orb for groudon on pokemon soul silver version or pokemon heart gold version but use action replay on pokemon pearl,diamond,platinum
At ruby version Groudon is level 45, at emerald Groudon is level 70.
Groudon is not obtainable on Pokemon gold. For more information on Pokemon visit bulbapedia.bulbagarden.net
u need 2 either catch groudon on soul silver and trade it onto heart gold yourself or u can find some1 else who has a groudon on soul silver and trade with them.
You can find groudon near meteor fals (search) Kyogre left of Pokemon league but you must have Pokemon with dive because is under water...
you can probably find it on Ebay
you trade kyorge from heart gold and go back to the place you caught groudon
you go to lyra in your house after you get all the gym bages in kanto and talk to her and there will be a earth quake
You find it in Route 224 using the Poke radar and there you go you've got it from Paul Myers
find a friend with the kyogre obtained from heart gold and reenter the tower and go find raquazya