Question: Windsor Beach, located in the northern portion of Lake Havasu, alongside the 1450 mi river, known as the "Colorado River", is administered by who?

Context paragraphs:
Windsor Beach, Lake Havasu: Windsor Beach is located in the northern portion of Lake Havasu on the Arizona side along the Colorado River.  The beach is administered by the Arizona State Parks.

Whipple Mountains Wilderness: The Whipple Mountains Wilderness is a 76122 acres wilderness administered by the Bureau of Land Management (BLM).  Most of the Whipple Mountains are within the wilderness area.  It is located in the northeastern Colorado Desert near the Colorado River.  Lake Havasu and Lake Havasu City are 25 mi to the south.  Earp, California and Parker, Arizona are 20 mi to the north.  The Parker Dam is 8 mi due east.

Mohave Mountains: The Mohave Mountains are a small 18-mi (29 km) long mountain range of northwest Arizona.  The range is a northwest trending range in southwest Mohave County that parallels a southeast-flowing stretch of the Colorado River, the Arizona-California border.  The range also forms the southwest border of a flatland region to its east and north, namely, Dutch Flat which lies east, at the south end of Sacramento Valley.  Lake Havasu City, AZ on the Colorado, lays opposite the southwest flank of the range, where the London Bridge was reconstructed at Lake Havasu.

Havasu National Wildlife Refuge: Havasu National Wildlife Refuge is a U.S. National Wildlife Refuge on the lower Colorado River in Arizona and California.  It preserves habitat for desert bighorn sheep to the endangered southwestern willow flycatcher, birds and other animals.  The refuge protects 30 river miles - 300 mi of shoreline - from Needles, California, to Lake Havasu City, Arizona.  One of the last remaining natural stretches of the lower Colorado River flows through the 20 mi Topock Gorge.

Colorado River: The Colorado River is one of the principal rivers of the Southwestern United States and northern Mexico (the other being the Rio Grande).  The 1450 mi river drains an expansive, arid watershed that encompasses parts of seven U.S. and two Mexican states.  Starting in the central Rocky Mountains in the U.S., the river flows generally southwest across the Colorado Plateau and through the Grand Canyon before reaching Lake Mead on the Arizona–Nevada border, where it turns south toward the international border.  After entering Mexico, the Colorado approaches the mostly dry Colorado River Delta at the tip of the Gulf of California between Baja California and Sonora.

Site Six, Lake Havasu: Site Six is located on the western point of Pittsburg Point in Lake Havasu on the Arizona side of the Colorado River.  Even though Site Six lies within the Lake Havasu State Park, Lake Havasu City manages this facility.

Bill Williams River: The Bill Williams River is a 46.3 mi river in west-central Arizona where it, along with its tributary, the Santa Maria River, form the boundary between Mohave County to the north and La Paz County to the south.  It is a major drainage westwards into the Colorado River of the Lower Colorado River Valley south of Hoover Dam and Lake Mead, and the drainage basin covers portions of northwest, and west-central Arizona.  The equivalent drainage system paralleling the east–west lower reaches of the Bill Williams is the Gila River, which flows east-to-west across central Arizona, joining the Colorado River in the southwest at Yuma.  The confluence of the Bill Williams River with the Colorado is north of Parker, and south of Lake Havasu City.

Lake Havasu: Lake Havasu is a large reservoir behind Parker Dam on the Colorado River, on the border between California and Arizona.  Lake Havasu City sits on the lake's eastern shore.  The reservoir has an available capacity of 619400 acre.ft .  The concrete arch dam was built by the United States Bureau of Reclamation between 1934 and 1938.  The lake's primary purpose is to store water for pumping into two aqueducts.  Prior to the dam construction, the area was home to the Mohave Indians.  The lake was named (in 1939) after the Mojave word for "blue".  In the early 19th century, it was frequented by beaver trappers.  Spaniards also began to mine the areas along the river.

Chimehuevis Landing, California: Chimehuevis Landing, a former river settlement, on the Colorado River, across from Lake Havasu City, in San Bernardino County, California, now a ghost town, but the location is now under Lake Havasu.

London Bridge (Lake Havasu City): London Bridge is a bridge in Lake Havasu City, Arizona.  It was built in the 1830s and formerly spanned the River Thames in London, England.  It was dismantled in 1967 and relocated to Arizona.  The Arizona bridge is a reinforced concrete structure clad in the original masonry of the 1830s bridge, which was purchased by Robert P. McCulloch from the City of London.  McCulloch had exterior granite blocks from the original bridge numbered and transported to America to construct the present bridge in Lake Havasu City, a planned community he established in 1964 on the shore of Lake Havasu.  The bridge was completed in 1971 (along with a canal), and links an island in the Colorado River with the main part of Lake Havasu City.  The song "London Bridge is Falling Down" is a nursery rhyme that predates the bridge's original 19th-century construction.

Supporting paragraphs: Windsor Beach, Lake Havasu Colorado River
Answer: Arizona State Parks