diff --git a/.DS_Store b/.DS_Store
new file mode 100644
index 0000000..529d84d
Binary files /dev/null and b/.DS_Store differ
diff --git a/lib/park.rb b/lib/park.rb
index e69de29..c33b870 100644
--- a/lib/park.rb
+++ b/lib/park.rb
@@ -0,0 +1,43 @@
+# lib/park.rb
+
+# The Park class represents a national park with vehicles, passengers, and revenue tracking.
+class Park
+  attr_reader :name, :price, :vehicles
+
+  # Initializes a Park with its name, admission price, and a list of vehicles.
+  def initialize(name, price)
+    @name = name           # The name of the park (e.g., Yellowstone).
+    @price = price         # The admission price per adult.
+    @vehicles = []         # A list of vehicles that entered the park.
+  end
+
+  # Adds a vehicle to the park.
+  def add_vehicle(vehicle)
+    @vehicles << vehicle
+  end
+
+  # Collects all passengers from all vehicles in the park.
+  def passengers
+    @vehicles.flat_map(&:passengers) # Combines all passengers from all vehicles.
+  end
+
+  # Calculates the total revenue generated by charging the admission price per adult.
+  def revenue
+    passengers.count(&:adult?) * @price # Multiply the number of adults by the price.
+  end
+
+  # Lists the names of all passengers, sorted alphabetically.
+  def patron_names
+    passengers.map(&:name).sort
+  end
+
+  # Lists the names of all minors (under 18), sorted alphabetically.
+  def minors
+    passengers.select { |p| !p.adult? }.map(&:name).sort
+  end
+
+  # Lists the names of all adults (18 and older), sorted alphabetically.
+  def adults
+    passengers.select(&:adult?).map(&:name).sort
+  end
+end
diff --git a/lib/passenger.rb b/lib/passenger.rb
index e69de29..e7a83de 100644
--- a/lib/passenger.rb
+++ b/lib/passenger.rb
@@ -0,0 +1,28 @@
+# lib/passenger.rb
+
+# The Passenger class represents a person in a vehicle.
+class Passenger
+  attr_reader :name, :age
+
+  # Initializes a Passenger with their name and age.
+  def initialize(details)
+    @name = details["name"] # Passenger's name.
+    @age = details["age"]   # Passenger's age.
+    @driver = false         # Tracks if the passenger is a driver (default: false).
+  end
+
+  # Determines if the passenger is an adult (18 or older).
+  def adult?
+    @age >= 18
+  end
+
+  # Checks if the passenger is currently a driver.
+  def driver?
+    @driver
+  end
+
+  # Updates the passenger's status to a driver.
+  def drive
+    @driver = true
+  end
+end
diff --git a/lib/vehicle.rb b/lib/vehicle.rb
index e69de29..44ee15b 100644
--- a/lib/vehicle.rb
+++ b/lib/vehicle.rb
@@ -0,0 +1,24 @@
+# lib/vehicle.rb
+
+# The Vehicle class represents a car with passengers.
+class Vehicle
+  attr_reader :year, :make, :model, :passengers
+
+  # Initializes a Vehicle with its year, make, and model.
+  def initialize(year, make, model)
+    @year = year            # The year the vehicle was manufactured.
+    @make = make            # The vehicle's make (e.g., Honda).
+    @model = model          # The vehicle's model (e.g., Civic).
+    @passengers = []        # A list to store passengers in the vehicle.
+  end
+
+  # Adds a passenger to the vehicle.
+  def add_passenger(passenger)
+    @passengers << passenger
+  end
+
+  # Counts the number of adult passengers in the vehicle.
+  def num_adults
+    @passengers.count(&:adult?) # Use `adult?` to count passengers who are adults.
+  end
+end
diff --git a/spec/.keep b/spec/.keep
deleted file mode 100644
index e69de29..0000000
diff --git a/spec/park_spec.rb b/spec/park_spec.rb
new file mode 100644
index 0000000..8977f78
--- /dev/null
+++ b/spec/park_spec.rb
@@ -0,0 +1,61 @@
+require_relative '../lib/park'
+require_relative '../lib/vehicle'
+require_relative '../lib/passenger'
+
+RSpec.describe Park do
+  before(:each) do
+    # Create a park and test data.
+    @park = Park.new("Yellowstone", 50)
+    @vehicle1 = Vehicle.new("2001", "Honda", "Civic")
+    @vehicle2 = Vehicle.new("2010", "Toyota", "Corolla")
+    @charlie = Passenger.new({"name" => "Charlie", "age" => 18})
+    @jude = Passenger.new({"name" => "Jude", "age" => 12})
+    @taylor = Passenger.new({"name" => "Taylor", "age" => 25})
+
+    # Add passengers to vehicles.
+    @vehicle1.add_passenger(@charlie)
+    @vehicle1.add_passenger(@jude)
+    @vehicle2.add_passenger(@taylor)
+  end
+
+  it 'exists and has attributes' do
+    # Check the park's attributes.
+    expect(@park.name).to eq("Yellowstone")
+    expect(@park.price).to eq(50)
+    expect(@park.vehicles).to eq([]) # Park starts with no vehicles.
+  end
+
+  it 'can add vehicles' do
+    # Add vehicles to the park.
+    @park.add_vehicle(@vehicle1)
+    expect(@park.vehicles).to eq([@vehicle1])
+  end
+
+  it 'can calculate revenue' do
+    # Add vehicles and calculate revenue from adult passengers.
+    @park.add_vehicle(@vehicle1)
+    @park.add_vehicle(@vehicle2)
+    expect(@park.revenue).to eq(100) # Charlie and Taylor generate revenue.
+  end
+
+  it 'can list patron names alphabetically' do
+    # Add vehicles and list passenger names alphabetically.
+    @park.add_vehicle(@vehicle1)
+    @park.add_vehicle(@vehicle2)
+    expect(@park.patron_names).to eq(["Charlie", "Jude", "Taylor"])
+  end
+
+  it 'can list minors alphabetically' do
+    # Add vehicles and list minors alphabetically.
+    @park.add_vehicle(@vehicle1)
+    @park.add_vehicle(@vehicle2)
+    expect(@park.minors).to eq(["Jude"])
+  end
+
+  it 'can list adults alphabetically' do
+    # Add vehicles and list adults alphabetically.
+    @park.add_vehicle(@vehicle1)
+    @park.add_vehicle(@vehicle2)
+    expect(@park.adults).to eq(["Charlie", "Taylor"])
+  end
+end
diff --git a/spec/passenger_spec.rb b/spec/passenger_spec.rb
new file mode 100644
index 0000000..46d8b42
--- /dev/null
+++ b/spec/passenger_spec.rb
@@ -0,0 +1,23 @@
+require_relative '../lib/passenger'
+
+RSpec.describe Passenger do
+  it 'exists and has attributes' do
+    # Create a passenger named Charlie who is 18 years old.
+    charlie = Passenger.new({"name" => "Charlie", "age" => 18})
+
+    # Check the passenger's attributes.
+    expect(charlie.name).to eq("Charlie")
+    expect(charlie.age).to eq(18)
+    expect(charlie.adult?).to eq(true)  # Charlie is an adult.
+    expect(charlie.driver?).to eq(false) # Charlie is not a driver by default.
+  end
+
+  it 'can update driver status' do
+    # Create a passenger and set them as a driver.
+    charlie = Passenger.new({"name" => "Charlie", "age" => 18})
+    charlie.drive
+
+    # Verify that the passenger is now a driver.
+    expect(charlie.driver?).to eq(true)
+  end
+end
diff --git a/spec/vehicle_spec.rb b/spec/vehicle_spec.rb
new file mode 100644
index 0000000..0243379
--- /dev/null
+++ b/spec/vehicle_spec.rb
@@ -0,0 +1,32 @@
+require_relative '../lib/vehicle'
+require_relative '../lib/passenger'
+
+RSpec.describe Vehicle do
+  before(:each) do
+    # Create a vehicle and passengers for testing.
+    @vehicle = Vehicle.new("2001", "Honda", "Civic")
+    @charlie = Passenger.new({"name" => "Charlie", "age" => 18})
+    @jude = Passenger.new({"name" => "Jude", "age" => 12})
+  end
+
+  it 'exists and has attributes' do
+    # Check the vehicle's attributes.
+    expect(@vehicle.year).to eq("2001")
+    expect(@vehicle.make).to eq("Honda")
+    expect(@vehicle.model).to eq("Civic")
+    expect(@vehicle.passengers).to eq([]) # Vehicle starts with no passengers.
+  end
+
+  it 'can add passengers' do
+    # Add a passenger to the vehicle.
+    @vehicle.add_passenger(@charlie)
+    expect(@vehicle.passengers).to include(@charlie)
+  end
+
+  it 'can count the number of adults' do
+    # Add passengers and count adults.
+    @vehicle.add_passenger(@charlie)
+    @vehicle.add_passenger(@jude)
+    expect(@vehicle.num_adults).to eq(1) # Only Charlie is an adult.
+  end
+end