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State Route 203

Click here for a key to the symbols used. An explanation of acronyms may be found at the bottom of the page.

Routing Routing

Rte 203From the Mono county line near Minaret Summit to Route 395.

Post 1964 Signage History Post 1964 Signage History

As defined in 1963, this route ran from "Mammoth Lakes to Route 395."

In 1967, Chapter 1323 extended the route from the Mono County Line to Mammoth Lakes: "the Mono county line near Minaret Summit Mammoth Lakes to Route 395."

Between US 395 and Mammoth Lakes, an "Old State Highway" parallels Route 203, taking a much more winding course along Mammoth Creek and running through Mammoth Creek Park. It reconnects with Route 203 at Sawmill Road, just west of the current interchange with the US 395 expressway. (This road is named "Old State Highway" in Compass's map and in Mapquest, but is named "Mammoth Creek Road" in MSN's mapping service.)

Note that the road actually does not end at Minaret Summit. Starting at US 395, the road is open all year round to the town of Mammoth Lakes at about 7,800 feet and to Mammoth Mountain Ski Area Main Lodge and Mammoth Mountain Inn at about 8,950 elevation. In the winter, the road is not plowed past that point. It opens to the public around mid June depending on the snow. It continues up to Minaret Summit, and then it goes down into The San Joaquin River Middle Fork valley (although past Minaret Summit, the road is not longer part of the state highway system, although it may be maintained by the park service). While in the valley there is a turn off for Devil’s Postpile. This turn off goes right to the river. During most of the summer there is a shuttle bus from Mammoth Mountain Inn to the San Joaquin River Middle Fork valley, Devil’s Postpile, and the 2 stables in the valley. From about 7:00 am to 7:00 pm most car traffic is not allowed and you have to take the shuttle bus. There is not enough parking in the valley. The road from the Inn to the summit is great. From the summit the road goes diagonally down a slope. This part of the road is narrow and sometimes downhill vehicles have to back up hill to allow uphill vehicles to pass. Usually if the vehicles are not too wide and drivers plan ahead only slowing down is needed. When the road gets to the valley it makes almost a complete U turn. It then goes down the valley a few miles. This part of the road is again wide enough for 2 way traffic. There are multiple bus stops in the valley. More information is available at for Devil’s Postpile. Fishing and camping are also possible in the valley. The John Muir Trail and Pacific Crest Trail are also down there.

There was once a proposal to extend Route 203/LRN 112 across the Sierras. At the time, in the throes of the Cold War and on the heels of World War II, where Eisenhower saw how the German war machine benefitted from the autobahns, the nation’s defense was one of the principal reasons forwarded for building the road. As Madera County Supervisor Carl W. McCollister said: “The road was necessary to give people in the San Joaquin Valley their rightful highway outlet to the east should coastal cities become targets of nuclear attack.” Ultimately, however, opponents of the road argued that the road was impractical and made zero business sense. Genny Smith, ringleader, organizer, activist, scribe who fought the road over nearly three decades, commented, “it was businessmen like Bob [Schotz] who made the difference. This road was a business proposition from the get-go and a poor one at that. He and his colleagues knew it and were willing to stand up and say so.” It was finally stopped during the Reagan Administration (as in, when he was Governor).
(Source: The Sheet, 8/2/2014, via AARoads)

Pre 1964 Signage History Pre 1964 Signage History

This was LRN 112, defined in 1933. It was not signed before 1964.

Status Status

In June 2016, the CTC authorized relinquishment of right of way in the Town of Mammoth Lakes along Route 203 between Mountain Boulevard and Minaret Road, consisting of a frontage road. The Town, by relinquishment agreement dated May 13, 2016, agreed to waive the 90-day notice requirement and accept title upon relinquishment by the State.

Scenic Route Scenic Route

[SHC 263.1] Entire route.

Interregional Route Interregional Route

[SHC 164.19] Entire route.

Other WWW Links Other WWW Links

Statistics Statistics

Overall statistics for Route 203:

Pre-1964 Legislative Route Pre-1964 Legislative Route

In 1935, Chapter 429 added the route “...from [LRN 26] near Oasis N-ly to Avenue 66 via Pierce Street.” with no number. In 1937, Chapter 841 deleted the 1935 definition and recreated it as LRN 203, with the same definition. This definition then remained unchanged until the 1963 renumbering.

This route ran from US 99 (present-day Route 86) near Oasis northerly to Avenue 66 via Pierce Street. This is part of present-day Route 195.

Acronyms and Explanations:

Back Arrow Route 202 Forward Arrow Route 204

© 1996-2020 Daniel P. Faigin.
Maintained by: Daniel P. Faigin <>.