diff --git a/lib/engine/game/g_18_royal_gorge/game.rb b/lib/engine/game/g_18_royal_gorge/game.rb
index 258a85152e..4cea2409f0 100644
--- a/lib/engine/game/g_18_royal_gorge/game.rb
+++ b/lib/engine/game/g_18_royal_gorge/game.rb
@@ -38,10 +38,114 @@ class Game < Game::Base
         TILE_LAYS = ([{ lay: true, upgrade: true, cost: 0 }] * 6).freeze
         MUST_BUY_TRAIN = :always
         CAPITALIZATION = :incremental
+        ESTABLISHED = {
+          'KP' => 1869,
+          'RG' => 1870,
+          'SPP' => 1872,
+          'PAV' => 1875,
+          'SF' => 1876,
+          'NO' => 1881,
+          'CM' => 1883,
+          'S' => 1887,
+          'FCC' => 1893,
+          'CSCC' => 1897,
+          'CS' => 1898,
+        }.freeze
+
+        EVENTS_TEXT = Base::EVENTS_TEXT.merge(
+          green_par: ['Green Par Available'],
+          brown_par: ['Brown Par Available'],
+        )
 
         def ipo_name(_entity = nil)
           'Treasury'
         end
+
+        def game_companies
+          YELLOW_COMPANIES.sort_by { rand }.take(2).sort_by { |c| c[:sym] } +
+            GREEN_COMPANIES.sort_by { rand }.take(2).sort_by { |c| c[:sym] } +
+            BROWN_COMPANIES.sort_by { rand }.take(1)
+        end
+
+        def game_corporations
+          # SF, RG, and three random corporations
+          corporations = INCLUDED_CORPORATIONS + MAYBE_CORPORATIONS.sort_by { rand }.take(3)
+
+          # sort by established year, to create yellow/green/brown tranches
+          corporations = corporations.sort_by { |c| ESTABLISHED[c[:sym]] }
+
+          # put established year on charter
+          corporations.map do |corporation|
+            corp = corporation.dup
+            corp[:abilities] = [{ type: 'base', description: "Est. #{ESTABLISHED[corp[:sym]]}" }]
+            corp
+          end
+
+          @log << "Railroads in the game: #{corporations.map { |c| c[:sym] }.join(', ')}"
+
+          corporations
+        end
+
+        def setup
+          @corporation_phase_color = {}
+          @corporations[0..1].each { |c| @corporation_phase_color[c.name] = 'Yellow' }
+          @corporations[2..3].each { |c| @corporation_phase_color[c.name] = 'Green' }
+          @corporations[4..4].each { |c| @corporation_phase_color[c.name] = 'Brown' }
+
+          @available_par_groups = %i[par]
+        end
+
+        def status_array(corporation)
+          if can_start?(corporation) || corporation.type == :metal
+            nil
+          else
+            ["Available in #{@corporation_phase_color[corporation.name]} Phase"]
+          end
+        end
+
+        def stock_round
+          Round::Stock.new(self, [
+            Engine::Step::DiscardTrain,
+            Engine::Step::Exchange,
+            Engine::Step::SpecialTrack,
+            G18RoyalGorge::Step::BuySellParShares,
+          ])
+        end
+
+        def can_start?(corporation)
+          case @phase.name
+          when 'Yellow'
+            @corporation_phase_color[corporation.name] == @phase.name
+          when 'Green'
+            @corporation_phase_color[corporation.name] != 'Brown'
+          else
+            true
+          end
+        end
+
+        def can_par?(corporation, parrer)
+          can_start?(corporation) && super
+        end
+
+        def event_green_par!
+          @log << "-- Event: #{EVENTS_TEXT[:green_par]} --"
+          @available_par_groups << :par_1
+          update_cache(:share_prices)
+        end
+
+        def event_brown_par!
+          @log << "-- Event: #{EVENTS_TEXT[:brown_par]} --"
+          @available_par_groups << :par_2
+          update_cache(:share_prices)
+        end
+
+        def par_prices
+          @stock_market.share_prices_with_types(@available_par_groups)
+        end
+
+        def corporation_opts
+          @players.size == 2 ? { max_ownership_percent: 70 } : {}
+        end
       end
     end
   end
diff --git a/lib/engine/game/g_18_royal_gorge/step/buy_sell_par_shares.rb b/lib/engine/game/g_18_royal_gorge/step/buy_sell_par_shares.rb
new file mode 100644
index 0000000000..9a6e1b4a2f
--- /dev/null
+++ b/lib/engine/game/g_18_royal_gorge/step/buy_sell_par_shares.rb
@@ -0,0 +1,17 @@
+# frozen_string_literal: true
+
+require_relative '../../../step/buy_sell_par_shares'
+
+module Engine
+  module Game
+    module G18RoyalGorge
+      module Step
+        class BuySellParShares < Engine::Step::BuySellParShares
+          def get_par_prices(entity, _corp)
+            @game.par_prices.select { |p| p.price * 2 <= entity.cash }
+          end
+        end
+      end
+    end
+  end
+end