Sid's Diner

The El Reno fried onion burger originated in the 1920s — the conventional historical claim places the invention at the Hamburger Inn (a small El Reno diner now closed) around 1926, though competing claims exist for other early El Reno restaurants. The technique was developed as a Depression-era thrift measure: ground beef was expensive, onions were cheap, and stretching the meat by smashing it onto a bed of onions effectively doubled the volume of the patty while reducing the meat cost per burger. What started as economic necessity became, almost accidentally, a distinctive cooking technique that produced a uniquely flavored burger.

The basic method is simple but exacting. A small ball of ground beef (typically 2-3 ounces) is placed on the hot flat-top grill. A generous mound of paper-thin sliced yellow onions — typically 1-2 ounces of onions per burger — is piled on top of the beef. The patty is then pressed flat with a heavy spatula, smashing the beef out into a thin wide patty with the onions pressed into the top. As the burger cooks, the onions release moisture and caramelize, the beef develops a heavy crust on the grill side, and when the burger is flipped, the onions become directly integrated into the meat surface.

Several El Reno restaurants have served onion burgers continuously since the original Depression-era invention — Sid's (in its current form since 1990 but the location and tradition older), Robert's Grill (operating since 1926, the oldest continuously-running onion-burger joint), and Johnnie's Grill (operating since 1949). All three serve essentially the same dish with minor variations in preparation. The annual El Reno Fried Onion Burger Day Festival held each May celebrates the tradition with a giant 750-pound onion burger cooked on a custom-built grill in downtown El Reno.

The Sid's space is genuinely tiny. The room is essentially a single narrow rectangle with the flat-top grill running along one wall and the counter with maybe 15 stools running along the opposite wall. The cook works the grill on one side of the counter; customers sit on stools on the other side, three feet away, watching the entire cooking process happen in real time. There are no booths, no tables, and no separate dining area — every customer experiences the burger preparation directly.

The menu is short and focused. The signature item is the onion burger, available as a single, double, or triple patty (Sid's Special), with or without cheese, and with or without standard burger condiments. Burgers run $4-7 depending on size and toppings. Sides are the standard short list — French fries, tater tots, onion rings — and drinks are fountain sodas, coffee, and occasionally milkshakes. The menu includes a handful of breakfast items (the diner opens at 7am for breakfast) and a few non-burger lunch options, but the onion burger is what 95% of visitors order.

The pace is intentional. The cook smashes each patty individually, so the kitchen does not operate at the high-throughput speed of a chain burger joint. During lunch peak (typically 11:30am to 1pm on weekdays, longer on Saturdays) there are often lines extending outside the door, and a 20-30 minute wait is not unusual on busy Saturdays. The waiting is part of the experience — visitors who arrive expecting fast-food efficiency are missing the point. Bring patience and the right expectations.

Sid Hall bought the location in 1990. The space had operated as various small downtown El Reno restaurants in the decades before — including periods serving the same Depression-era onion-burger tradition — and Sid's acquisition was the move that transformed the operation into the destination it is today. Sid personally worked the grill through most of the 1990s and 2000s, taking orders, smashing patties, and chatting with the steady stream of locals and travelers across the counter. His commitment to the traditional preparation method (no shortcuts, no pre-formed patties, no frozen beef) became central to Sid's identity.

Media attention built gradually through the 1990s and 2000s — regional travel guides, Oklahoma food coverage, Food Network specials. The most influential single piece of media coverage was Anthony Bourdain's Parts Unknown Oklahoma episode, which featured a Sid's onion-burger segment and introduced the El Reno tradition to a national and international audience. Tourist visitation to Sid's increased substantially after the Bourdain episode, and the diner became a regular fixture on Route 66 'must-stop' lists in major travel publications.

Sid himself has stepped back from day-to-day operations in recent years; the diner continues with family and staff continuity that has been in place for years. The preparation, the menu, and the bare-bones counter-service experience have remained essentially unchanged. The diner is closed Sundays and operates Monday through Saturday from 7am to 3pm — note the early afternoon closing time, which catches some visitors off guard who plan late lunches without checking hours.

Many visitors do both Sid's and Robert's Grill in a single El Reno onion-burger pilgrimage. The two joints are two blocks apart in downtown El Reno (Sid's on Choctaw, Robert's on Bickford) and serve essentially the same Depression-era specialty with minor preparation differences. The comparison is genuinely interesting: Sid's onions are sometimes described as slightly more caramelized, Robert's as slightly thinner and crispier; Sid's draws more out-of-town traffic, Robert's more locals. Both are excellent and most Route 66 travelers split a burger at each rather than ordering full meals.

Payment historically was cash-only at most El Reno onion-burger joints — a tradition that aligned with the bare-bones counter-service ethos. Card acceptance has gradually expanded across the El Reno classics; visitors should bring cash to be safe but most spots now accept cards. ATMs are available within walking distance in downtown El Reno. Tipping is appreciated but not heavily expected given the counter-service format; rounding up to the next dollar or leaving a few dollars on a $20+ order is standard.

The natural El Reno day plan: morning at Fort Reno (9am-11am), Canadian County Historical Museum (11am-12pm), lunch at Sid's or split between Sid's and Robert's (12pm-1pm), afternoon continuing west on Route 66 toward Clinton, Elk City, and the western Oklahoma corridor. El Reno is 25 miles east of Oklahoma City (a 30-minute drive on I-40) and 60 miles east of Clinton, making it a natural mid-morning or lunchtime stop on a westbound Route 66 day from OKC.