State Road 951 (SR 951), locally known as Collier Boulevard, is a north–south divided highway that extends from the south end of the Judge S.S. Jolley Bridge in Marco Island to the Tamiami Trail (U.S. Route 41 (US 41)/SR 90) near Naples Manor, along with a short piece between SR 84 and Interstate 75 (I-75). The highway once extended over long, traveling between Marco Island and SR 846 near Golden Gate. Portions of the former state highway are now part of County Road 951 (CR 951). Route description State Road 951 begins at the south end of the S.S. Jolley Bridge in Marco Island, crossing Big Marco Pass, passing through marshland and woodland as it leaves Marco Island and heads towards the mainland, crossing an intersection with CR 952 (Capri Boulevard). The next intersection, Mainsail Drive, provides access to Marco Island Airport. Further north on the mainland, the road passes by some newer housing and country club developments as it intersects with Tamiami Trail, the northern terminus of the southern segment. The road resumes near Golden Gate at SR 84's eastern terminus on Florida's Gulf Coast, and has an interchange with I-75 at the west end of Alligator Alley, with the northern end of the interchange being the northern terminus. A numbering anomaly within the Florida Department of Transportation’s numbering system of State Roads, SR 951 is the only SR 9xx highway that is not in Miami-Dade County: Krome Avenue (SR 997) lies to the east; the similarly numbered SR 953 (LeJeune Road) is another to the east of SR 997. History Most of the current portion of State Road 951 south of U.S. Route 41 came into existence around 1955 during development of the Isles of Capri. It was built upon the abandoned rail bed of the Atlantic Coast Line Railroad's Fort Myers to Marco Island branch, which existed from 1927 to 1944. Prior to 1976, State Road 951 extended along a much longer route than it does today. It began at the Isles of Capri (along the current CR 952). When the Jolley Bridge was built to Marco Island in 1969, the route across it was designated SR 951B. At State Road 84 (the original Alligator Alley and current Davis Boulevard), SR 951's designation then zig-zagged into North Naples along what is today Radio Road, Airport-Pulling Road, Golden Gate Parkway and Goodlette-Frank Road, ultimately terminating at the intersection